| RefNo | Title | Date |
| NLB/63/212 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Dr. [Hans Frederich] Gadow, FRS | 17 July 1922 |
| IM/Maull/001586 | Gadow, Hans Friedrich | nd |
| NLB/24/201 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, [Fellow of the Royal Society], Zoological Laboratory, Cambridge | 21 March 1902 |
| NLB/2/433 | Copy letter from an unknown correspondent, to the Cambridge Scientific Instrument Company | 27 June 1888 |
| NLB/6/541 | Copy letter from Herbert Rix, to Dr Hans Friedrich Gadow, Morphological Laboratory, Cambridge | 30 May 1892 |
| NLB/6/1115 | Copy letter from Theodore E James to Messrs Harrison & Sons | 27 October 1892 |
| NLB/6/1039 | Copy letter from Herbert Rix, to Dr Hans Friedrich Gadow, Morphological Laboratory, Cambridge | 7 October 1892 |
| NLB/10/380 | Copy letter from Herbert Rix, to Mr G Pearson, 3 Bolt Couty, Fleet Street, E.C. | 16 November 1894 |
| NLB/37/399 | Copy letter from Robert William Frederick Harrison to Dr Hans [Friedrich] Gadow | 11 March 1908 |
| NLB/12/32 | Copy letter from an unknown correspondent, to Mr E Wilson, Post Office Terrace, Cambridge | 23 November 1895 |
| NLB/11/790 | Copy letter from Herbert Rix, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 7 October 1895 |
| NLB/12/377 | Copy letter from Herbert Rix, to Mr E Wilson, Post Office Terrace, Cambridge | 11 February 1896 |
| NLB/11/889 | Copy letter from an unknown correspondent, to Mr Collings, 172 Strand | 29 October 1895 |
| NLB/11/935 | Copy letter from Herbert Rix, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 6 November 1895 |
| NLB/12/268 | Copy letter from Herbert Rix, to Dr Hans Friedrich Gadow, Fellow of the Royal Society, University Museum of Zoology, Cambridge | 17 January 1896 |
| NLB/12/2 | Copy letter from Herbert Rix, to Professor Edwin Ray Lankester, Fellow of the Royal Society | 16 November 1895 |
| NLB/12/244 | Copy letter from Herbert Rix, to Professor Michael Foster, Secretary, Royal Society | 13 January 1896 |
| RR/15/195 | Referee's report by Hans Friedrich Gadow, on a paper 'The anatomy of symmetrical double monstrosities in the trout' by James Fairlie Gemmill | March 1901 |
| RR/16/3 | Referee's report by Hans Friedrich Gadow, on a paper 'On the evolution of the Proboscidea' by Charles William Andrews | 23 March 1903 |
| RR/17/384 | Referee's report by Hans Friedrich Gadow, on a paper 'The intercranial vascular system of sphenodon' by Arthur Dendy | April 1909 |
| NLB/15/118 | Copy letter from Robert William Frederick Harrison, to Professor Edwin Ray Lankester, Fellow of the Royal Society | 30 June 1897 |
| RR/17/34 | Referee's report by Hans Friedrich Gadow, on a paper 'On the development of the head-muscles of the common fowl (Gallus domesticus), together with some remarks on the head-muscles of reptiles' by F H Edgeworth | 25 May 1906 |
| RR/17/114 | Referee's report by Hans Friedrich Gadow, on a paper 'On the skull, mandible, and milk dentition of Palæomastodon, with some remarks on the tooth change in the proboscidea in general' by Charles William Andrews | [July 1907] |
| NLB/15/168 | Copy letter from Michael Foster, to Dr Hans Friedrich Gadow, [Fellow of the Royal Society] | 8 July 1897 |
| NLB/15/635 | Copy letter from Robert William Frederick Harrison, to Professor Edwin Ray Lankester, Fellow of the Royal Society | 9 November 1897 |
| NLB/16/62 | Copy letter from Robert William Frederick Harrison, to Professor E Ray Lankester, Fellow of the Royal Society | 22 January 1898 |
| NLB/24/230 | Copy letter from Theodore E James, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 8 April 1902 |
| NLB/19/539 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 28 October 1899 |
| NLB/19/350 | Copy letter from Michael Foster, to Edwin Ray Lankester, [Fellow of the Royal Society] | 22 August 1899 |
| NLB/19/533 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 26 October 1899 |
| NLB/22/274 | Copy letter from Robert William Frederick Harrison, to Dr [Hans Friedrich] Gadow, Fellow of the Royal Society | 3 April 1901 |
| NLB/23/2/385 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 28 October 1903 |
| NLB/23/1/256 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 17 October 1901 |
| NLB/24/237 | Copy letter from Theodore E James, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 10 April 1902 |
| NLB/23/2/386 | Copy letter from Sir Michael Foster, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 5 November 1903 |
| NLB/23/1/663 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 21 December 1901 |
| NLB/27/162 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 14 July 1903 |
| NLB/31/83 | Copy letter from Robert William Frederick Harrison, to Dr Hans Freidrich Gadow, Fellow of the Royal Society | 19 June 1905 |
| NLB/37/240 | Copy letter from Robert William Frederick Harrison to Dr H [Hans Freidrich] Gadow FRS | February 20 1908 |
| NLB/35/643 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 24 June 1907 |
| NLB/37/220 | Copy letter from Robert William Frederick Harrison to Dr H [Hans Frederick] Gadow FRS | 17 February 1908 |
| NLB/40/138 | Copy letter from Robert William Frederick Harrison to Dr H [Hans Friedrich] Gadow FRS | 23 April 1909 |
| NLB/37/373 | Copy letter from The Royal Society, to Dr Gadow Fellow of the Royal Society, Zoological Laboratory, Cambridge | 9 March 1908 |
| NLB/37/877 | Copy Letter from Robert William Frederick Harrison to Sir William Crookes, Fellow of the Royal Society | 28 May 1908 |
| NLB/40/157 | Copy letter from Robert William Frederick Harrison to Dr H [Hans Friedrich] Gadow FRS | 26 April 1909 |
| NLB/40/344 | Copy letter from Robert William Frederick Harrison to Dr Hans [Friedrich] Gadow FRS | 26 May 1909 |
| NLB/40/70 | Copy letter from Robert William Frederick Harrison to Dr S [Sidney] F [Frederic] Harmer FRS | 2 April 1909 |
| NLB/40/82 | Copy letter from Robert William Frederick Harrison to Dr H [Hans] F [Friedrich] Gadow FRS | 5 April 1909 |
| NLB/41/805 | Copy letter from Robert William Frederick Harrison, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 1 March 1910 |
| NLB/45/454 | Copy letter from Robert William Frederick Harrison to Dr H [Hans Friedrich] Gadow FRS | 7 March 1912 |
| RR/29/18 | Referee's report by Hans Friedrich Gadow, on a paper 'On the classification and phylogeny of the teleostei arterioles' by H K Kyle | 23 January 1923 |
| RR/9/353 | Referee's report by Thomas Henry Huxley, on a paper 'Remarks on the cloaca and on the copulatory organs of the amniota' by Hans Friedrich Gadow | 10 June 1886 |
| RR/10/171 | Referee's report by Edwin Ray Lankester, on a paper 'On the the modifications of the first and second visceral arches, with especial reference to the homologies of the auditory ossicles' by Hans Friedrich Gadow | 13 June 1888 |
| RR/9/352 | Referee's report by William Henry Flower, on a paper 'Remarks on the cloaca and on the copulatory organs of the amniota' by Hans Friedrich Gadow | 1 May 1886 |
| RR/10/172 | Referee's report by Arthur Milnes Marshall, on a paper 'On the the modifications of the first and second visceral arches, with especial reference to the homologies of the auditory ossicles' by Hans Friedrich Gadow | 17 June 1888 |
| NLB/55/213 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to [Hans Frederich] Gadow, FRS | 16 January 1918 |
| RR/12/109 | Referee's report by Thomas Henry Huxley, on a paper 'On the evolution of the vertebral column of fishes' by Hans Friedrich Gadow and E C Abbott | 18 July 1894 |
| RR/19/95 | Referee's report by Hans Friedrich Gadow, on a paper 'The circulatory system of the common grass snake, Tropidonotus natrix' by Charles Henry O'Donoghue | [March 1912] |
| NLB/68/19 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Dr [Hans Friedrich] Gadow, FRS | 28 April 1925 |
| NLB/69/322 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Dr. [Hans Friedrich] Gadow, FRS | 2 March 1926 |
| NLB/69/83 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Sir Sidney Harmer, K.B.E, FRS | 6 January 1926 |
| NLB/68/884 | Copy letter from William Bate Hardy, Secretary of the Royal Society; to Dr [Hans] Gadow, FRS | 20 November 1925 |
| NLB/71/505 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Prof. [David Meredith Seares] Watson, FRS | 19 June 1928 |
| NLB/71/649 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Prof. [David Meredith Seares] Watson, FRS | 21 September 1928 |
| NLB/72/653 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Professor [David Meredith Seares] Watson, FRS | 14 February 1930 |
| EC/1892/12 | Gadow, Hans Friedrich: certificate of election to the Royal Society | |
| NLB/6/526 | Copy letter from Herbert Rix, to Mr John Evans, Treasurer, Royal Society | 26 May 1892 |
| NLB/10/384 | Copy letter from Herbert Rix, to Dr Hans Friedrich Gadow, Fellow of the Royal Society | 16 November 1894 |
| NLB/11/516 | Copy letter from Michael Foster, to His Excellency, The Spanish Ambassador | 16 July 1895 |
| NLB/15/142 | Copy letter from Robert William Frederick Harrison, to Professor Michael Foster, Fellow of the Royal Society | 6 July 1897 |
| NLB/37/146 | Copy letter from the The Secretary, the Royal Society to The Secretary, The Foreign Office | 31 January 1908 |
| NLB/42/9 | Copy letter from Robert William Frederick Harrison to Dr H [Hans Friedrich] Gadow FRS | 7 March 1909 |
| RR/37/117 | Referee's report by Hans Friedrich Gadow, on a paper 'The study of the development of the vertebral column of amphibia, as shown in the life-history of rana temporaria' by Himadri Kumar Mookerjee | April 1928 |
| NLB/69/487 | Copy letter from [Francis Alexander Towle, Assistant Secretary of] the Royal Society; to Dr. [Hans Friedrich] Gadow, FRS | 3 May 1926 |
| NLB/69/133 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Dr. [Hans Friedrich] Gadow, FRS | 18 January 1926 |
| NLB/10/33 | Copy letter from A H White, to Dr Michael Foster, Secretary, Royal Society | 6 September 1894 |
| RR/12/320 | Referee's report by Walter Frank Raphael Weldon, on a paper 'On the evolution of the vertebral column of amphibia and amuivta' by Hans Friedrich Gadow | 26 October 1893 |
| MDA/C/12/2/8 | Letter from Hans Friedrich Gadow, University Museum of Zoology, Cambridge, to William Abbott Herdman, Chairman, Zoology Committee | 26 June 1901 |
| RR/12/110 | Referee's report by Walter Frank Raphael Weldon, on two papers 'On the evolution of the vertebral column of fishes' by Hans Friedrich Gadow and E C Abbott, and 'On the structure and affinities of Heliopora coerulea, Pallas. With some observations on the structure of Xenia and Heteroxenia' by Gilbert Charles Bourne | 8 August 1894 |
| RR/11/123 | Referee's report by Hand Friedrich Gadow, on a paper 'Contributions to the anatomy of fishes. II. The air-bladder and Weberian ossicles in the siluroid fishes' by Thomas William Bridge and Alfred Cort Haddon | 26 September 1892 |
| RR/12/319 | Referee's report by Edwin Ray Lanester, on a paper 'On the evolution of the vertebral column of amphibia and amuivta' by Hans Friedrich Gadow | 9 August 1895 |
| RR/24/88 | Referee's report by Hans Friedrich Gadow, on a paper 'The structure, evolution and origin of the Amphibia. - The "orders' Rachitomi and Stereospondyli' by David Meredith Seares Watson | 22 March 1917 |
| RR/36/43 | Referee's report by Hans Friedrich Gadow, on a paper 'On the evolution of the vertebral column in birds, illustrated by its development in Larus and Struthio' by Johannes Piiper | [June 1927] |
| MC/15/273 | Letter from [Hans Friedrich] Gadow, Zoological Society of London, to Professor [Michael] Foster | 5 May 1892 |
| MC/15 | Volume 15 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1889-1892 |
| NLB/37/138 | Copy letter from Robert William Frederick Harrison to Dr H [Hans Frederick] Gadow FRS | 30 January 1908 |