202 Transactions. — Zoology. 



would thus become more widely knowu, and the ratio of their 

 increase would be cumulative. Exchanges could also be car- 

 ried on, if desirable, with museums in other countries, and col- 

 lections of great variety, magnitude, and value might thus be 

 readily formed. In fact, the Museum would have such great 

 advantages over private individuals that its collections would 

 soon become the accepted standards for reference. 



Few branches of natural science are now regarded as of 

 greater importance than the geographical distribution of 

 organisms. The occurrence of the same species and genera of 

 animals and plants at remote localities on the earth's surface 

 has been often regai'ded, by geologists and others, as affording 

 the best evidence of the configuration of the land and water 

 in long-past epochs of the world's history. Many other facts 

 have been derived from a careful comparison of forms of life 

 obtained at widely-distant localities. These are related in a 

 most concise and masterly manner by Charles Darwin in that 

 truly marvellous work " The Origin of Species." With your 

 permission, I will briefly quote two examples as instances of 

 what may be learned from geographical distribution. It has 

 been noticed that a very close relationship exists between the 

 marine productions on each side of the Isthmus of Panama, a 

 fact apparently only to be explained by the existence of an 

 opening between the two Americas at a period not sufficiently 

 remote to have allowed any important modifications to have 

 occurred in the organisms on each side of the present isthmus. 

 There is also a very close relationship between the high alpine 

 fauna and flora and the arctic fauna and flora all round the 

 world in the Northern Hemisphere, apparently indicating that 

 at one time the intervening lowlands were under an arctic 

 climate, a gradual increase in heat driving the organisms 

 northwards and to the mountain-tops, where they now remain 

 as isolated survivals, the inhabitants of the most remote sum- 

 mits showing the closest possible resemblance to one another. 

 These, and many other facts of equal interest and importance, 

 have been derived from our scanty knowledge of geographical 

 distribution, and it may be reasonably anticipated that other 

 equally-important facts will be discovered as our knowledge in 

 this direction increases. 



It is almost unnecessary to state that no approach to a 

 complete knowledge of the geographical distribution of living 

 beings can be attained without the formation of exhaustive 

 collections in each country. One effect of modern civilisation 

 is to alter the ancient distribution of all organisms ; and the 

 importance of speedy attention to this branch of knowledge 

 is manifest, unless, indeed, we are content to let everything go, 

 and thus forbid any accurate knowledge of the prehistoric 

 earth from ever being obtained. The importance of New 



