472 PEOr. B. C. A. WINDLE OlST TEEATOI/OGICAL EVIDENCE 



"When we come to inquire into the causation of these defects, 

 we find various theories given to account for them. Virchow *, 

 writing of branchial and other clefts, says that without particu- 

 larizing whether traumatic, thermic, or other causes act, the 

 main fact is that the defects arise from an irritative process. 

 Some may call this inflammatory ; in any case it is not passive but 

 active. Some forms of palatine and facial clefts have, he thinks, 

 a similar origin in an early inflammation. It should be men- 

 tioned that this was written as long ago as 1855, and that the 

 theory which accounts for many defects by foetal inflammation 

 has lost much ground since then. The defect may be due 

 to deficiency of material, and this again, it seems possible, may 

 be due to mal-nutrition by the mother. I quote the following 

 passage from Oakley Coles's interesting chapter on the etiology of 

 cleft-palate, to which I shall have to recur in a later section f: — 

 " Dr. Ogle has called attention to the fact that 99 per cent, of 

 the lion-cubs born in the London Zoological Gardens have cleft- 

 palates, and he has referred this curious phenomenon to the 

 artificial diet necessitated by the enforced captivity. It has, 

 indeed, been contended, in reply to this theory, that the experi- 

 ence of the London Zoological Society is exceptional, differing 

 from that of other menageries, and Mr. Pollock J has suggested 

 that we must seek for the cause of the phenomenon amongst 

 other conditions than the food-supply. It is true that among 

 the lion-cubs born in the Dublin Gardens, cleft-palate is seldom 

 noticed ; but it is stated that it used to occur quite as 

 frequently as in London, when the feeding was conducted in a 

 similar way, viz. by supplying only the meat of large animals. 

 Now, however, that the lions are given goat twice a week, which 

 they can eat bones and all, the proportion of cleft-palate has 

 become quite insignificant. These observations seem to point to 

 the possibility of cleft-palate in the human subject being due to 

 an analogous departure from a natural diet amongst civilized 

 nations, but it is at all times perilous to argue from the lower 

 animals to man. At any rate the evidence at present before us 

 does not admit of anything more than conjecture." If the in- 



* " Ueb. Missbild am Ohr u. iin Bereiclie des erstens Kiemenbogens," Virch. 

 Arcb. Bd. 30. p. 221. 

 i- ' Deformities of the Moutb ' (Loud. 1887), p. 37. 

 t Holmes's System of Surgery, vol. It. p. 420. 



