360 Mr. W. K. Parker on the Skull of Salmo salar. [May 30, 





Cornea. 



Sclerotic. 



Lens. 



Ciliary 



Elastic ligament. 





Muscle. 



Posterior. 



Anterior. 





( 



in. 



vertical f§ 



in. 



vertical l£ 



lateral 



in. 



ti 



in. 



A 



in. 



A 



in. 



3 

 TTF 



Ehea ameri- _ 





lateral f| 



lateral 



















ant.-post.l/o 





11 



fibres long. 







Phcenicopterus 

 antiquorum 



r 



vertical 



lateral -fa 

 more 



lateral 

 ant.-post. 



lateral 

 ant.-post. 



A 

 A 



tV 



gradually di- 

 minishing. 



A 



a 



II 



Aptenodytcs \ 

 Hiimboldtii j 



H 



lateral jf- 

 ant.-post. }f 



lateral 

 ant.-post. 



A 



A 



gradually di- 

 minishing. 



A 



A 



The Society then adjourned over the Whitsuntide Recess to Thursday, 

 May 30. 



May 30, 1872. 



GEORGE BIDDELL AIRY, C.B., President, in the Chair. 



The Bakerian Lecture was delivered by William Kitchen 

 Parker, F.R.S., " On the Structure and Development of the 

 Skull of the Salmon {Salmo salar, L.)." The following is an 

 Abstract. 



A few years ago Mr. Waterhouse Hawkins put into my hands some 

 newly hatched salmon and also three of the first summer. Seeing their 

 fitness for embryological research and the interest attaching to the formation 

 of an osseous fish, I applied to my friends Messrs. Frank Buckland and 

 Henry Lee, and these gentlemen most liberally supplied me with a large 

 number of unhatched embryos and of the "fry" of this large fish. 



My last subject, the frog, being fairly out of hand, I set myself last 

 summer to this newer and more easy task, — more easy by far, for the 

 translucency of the young salmon contrasts most favourably with the 

 obscurity of the embryo frog. 



I found that the two types at the time of hatching did not start fairly, 

 but that the salmon had hastened to finish its fourth stage before emerging 

 from the egg ; this, however, is partly in consequence of the difference of 

 the envelope in which the embryos are contained ; for in the salmon this 

 is a leathery "chorion," and in the frog a mere gelatinous bleb. 



Moreover, it soon became apparent that these two " Ichthyopsidans" are 



