MONSTROSITIES 321 



rather an encumbrance and a disadvantage, and its possessors 

 rnight soon become extinct ; or 



{b) It would have appropriate nerves and muscles ; and then 

 Its owner would soon learn to make use of it for its own advantage, 

 and being. congenital it would be inherited. 



We have seen that supernumerary digits may be either simple 

 appendages of the skin, without phalanges, muscles, or nerves ; or 

 they may be as well furnished with all three, and indistinguishable 

 from other digits. A savage born with hands and feet like those 



Fig. 95. — Monstrous hand and foot from Anomalies de I' Organisation, by Isidore 

 Geoffroy St. Hilaire, vol. iii. 



shown in Fig. 95, would indubitably have more power in both than 

 another born with hands and feet like those of Fig. 96, or perhaps 

 than others born with the ordinary number. And so of other 

 monstrosities which may have occurred in geological times, and 

 which may have had their monstrous parts furnished with means 

 for using them as weapons either of offence or defence, or for main- 

 taining their hold on their surroundings. 



We have little knowledge as to the process by which some 

 cells of the embryo turn into muscles, others into nerves, and so 

 forth. All we know is that after the egg has subdivided itself into a 



X 



