717 



Table II. Stern alls muscle in anencephalous foetuses. 



DwiGHT *) states that he has found it once only out of four or 

 six specimens examined. 



From the table it appears that the muscle is to be found in 50 per 

 cent of all anencephalous foetuses and far more frequently bilaterally 

 than unilaterally. It thus exists in a much larger proportion of these 

 forms than in normal in which the average is from 3 to 5 per cent. 

 The number of foetuses affected with other malformations which I have 

 examined is perhaps too small to enable one to draw definite conclu- 

 sions, but so far as the figures go they prove that the muscle is more 

 common in the anencephalous form than in others. I may mention 

 that Cunningham and Shepherd have each examined a specimen of 

 Cyclops but without finding a sternahs. If the muscle be, as has 

 been suggested, a reversion, it is very difficult to understand why it 

 should show such a preference for the anencephalous form. — Up to 

 the present, it may safely be said, that the connection between anen- 

 cephaly and the sternalis muscle is shrouded in mystery. 



Ine the second place, the variety and closeness of its connection 

 with the pectoralis major should be noted. It is no part of my inten- 

 tion to criticise in detail the theories which have been put forward to 

 explain its morphology, by Turnee, Cunningham, Bardeleben and 

 others whose writings on the subject are too well known to require 

 further mention. For my own part Cunningham's observations on the 

 nerve supply settle the question as to its pectoral nature in my mind. 



1) Transactions of Academy of Medicine in Ireland, 1883. 



2) Journal of Anatomy and Physiology, vol. XIX, p, 312; ib. vol. 

 XXIII, p. 301. 



3) Journal of Anatomy and Physiology, vol. XXII, p. 391. 



4) Journal of Anatomy and Physiology, vol. XXII, p. 96. 



