VIKWS OK NATlMtK < ONTKASTKI). 13 



siiugle, but it otlioiwi.sc reseiiible.s the tliix-o hoiiu.s c'oml>ine<l 

 of the salmon, and the three elements of that type evidently 

 are the (lisint(;;:;rated representatives of the solid eartilage of 

 the ti^ar. Note also that two diverging; cartilages partly 

 b(»und and partly intervene between the basal bones and the 

 pectoral tin an<l earlilagiinous pieces just described. If now. 

 time and the occasion ]»ermitted, I might submit to you 

 other forms, but I trust I have adduced sufiicicnt to render 

 it possil)le for your judgments to acce])t the following jtroji- 

 ositions as at least not inii)rob:iMi . 



The pectoral fin and sustaining arch of the lishes in its 

 several elements are referable to two categoriiis. 



The rays, the longish bones at their bases, and the bones 

 or cartilages that bound or inclose them must be considered 

 as the equivalents of the fore limb of quadrupeds. 



The shoulder girdle is to be considered as representing 

 the scapula of land animals, but with certain additions. 



The projecting l)a]l-likc tubercle of jwli/ptcriis is of es- 

 * pecial signiticance. 



Look, now, at the pectoral tin oi' pal i/pterui^, and compare 

 ii with the fore lind.) of a (juadruped : you can appreciate 

 some resemblance, I think, between (1) the diverging pro- 

 cesses thereof and radius and ulna. (2) The wrist or carpus 

 may be formed out of the included and succeeding cartilage 

 of polijptcrus. (o) The metacarpals are at lea.st simulated 

 by the longish parallel l)ones at the base of the rays. (4) 

 The phalanges may be represented by the pectoral rays. 

 Tlie humerus is still to be accounted for, and I am inclined 

 to believe that it is represented by the constricted peduncle 

 that supjiorts the first named bones. Whether the relations 

 thus indicated are true homological exjuessions has to be 

 still ]»roved, but they are, I venture to think, probable. 

 But the very doubt, still involving the (juestion is, at least, 

 one o\ the most cogent evidences of th(! great gap between 

 the whales and the fishes. 



If I am right in the conjectures thus ad<luced you will 

 now see that while the fore limb, bone lor bone, is tlu; .same 

 in the whale as in the quailruped, it is only j)artially repre- 



