38 UNITY OF TYPE 



the same end and then we should have cases of 

 analogy 1 , [they might even tend to become numeri- 

 cally representative]. From this often happening 

 each of the great divisions of nature would have 

 their representative eminently adapted to earth, to 

 (air) 2 , to water, and to these in (illegible) and then 

 these great divisions would show numerical relations 

 in their classification. 



vm. UNITY [OR SIMILARITY] OF TYPE IN THE 



GREAT CLASSES. 



Nothing more wonderful in Nat. Hist, than look- 

 ing at the vast number of organisms, recent and 

 fossil, exposed to the most diverse conditions, living 

 in the most distant climes, and at immensely remote 

 periods, fitted to wholely different ends, yet to find 

 large groups united by a similar type of structure. 

 When we for instance see bat, horse, porpoise-fin, 

 hand, all built on same structure 3 , having bones 4 with 

 same name, we see there is some deep bond of union 

 between them 5 , to illustrate this is the foundation and 

 objects (?) (of) what is called the Natural System; 

 and which is foundation of distinction (?) of true and 

 adaptive characters 6 . Now this wonderful fact of 

 hand, hoof, wing, paddle and claw being the same, is 

 at once explicable on the principle of some parent- 

 forms, which might either be (illegible) or walking 

 animals, becoming through infinite number of small 



1 The position of the following is uncertain, " greyhound and racehorse 

 have an analogy to each other." The same comparison occurs in the Origin, 

 Ed. i. p. 427, vi. p. 583. 



2 Air is evidently intended; in the MS. water is written twice. 



3 Written between the lines occurs :" extend to birds and other 

 classes." 



4 Written between the lines occurs: "many bones merely represented." 



5 In the Origin, Ed. i. p. 434, vi. p. 595, the term morphology is taken 

 as including unity of type. The paddle of the porpoise and the wing of 

 the bat are there used as instances of morphological resemblance. 



c The sentence is difficult to decipher. 



