VII THE STUDY OF ZOOLOGY 209 



transitional forms are known, that the members of 

 the sub-kingdoms are disconnected from, or inde- 

 pendent of, one another. On the contrary, in 

 their earliest condition they are all similar, and the 

 primordial germs of a man, a dog, a bird, a fish, a 

 beetle, a snail, and a polype are, in no essential 

 structural respects, distinguishable. 



In this broad sense, it may with truth be said, 

 that all living animals, and all those dead faunae 

 which geology reveals, are bound together by an 

 all-pervading unity of organisation, of the same 

 character, though not equal in degree, to that 

 which enables us to discern one and the same plan 

 amidst the twenty different segments of a lobster's 

 body. Truly it has been said, that to a clear eye 

 the smallest fact is a window through which the 

 Infinite may be seen. 



Turning from these purely morphological con- 

 siderations, let us now examine into the manner in 

 which the attentive study of the lobster impels us 

 into other lines of research. 



Lobsters are found in all the European seas ; 

 but on the opposite shores of the Atlantic and in 

 the seas of the southern hemisphere they do not 

 exist. They are, however, represented in these 

 regions by very closely alHed, but distinct forms 

 the Hcmarus Americanus and the Homarus 

 Capensis : so that we may say that the European 

 has one species of Homarus ; the American, 

 another; the African, another; and thus the 

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