79 
1914-15.] Regeneration of the Legs of Decapods. 
my thanks are also due for sound practical aid,"*^ Dr J. F. Geramill 
supplied me with references to literature on the subject, and I have to 
acknowledge my gratitude to him on that account. I have also to thank 
him for facilities for working in the Embryological Laboratory, Glasgow 
University. 
Historical. 
For more than two centuries regeneration of limbs in decapod crus- 
taceans has drawn the attention of biologists. While a great deal of 
information has been obtained regarding the conditions and extent of 
reproduction, the veil of mystery hangs as darkly over many points 
connected with it as over most vital phenomena. 
Reaumur (1) (1712) first described the regeneration of legs in crabs, 
lobsters, and crayfish, though Du Tertre had drawn attention to it as early 
as 1654. The following extract from the work of Reaumur is quoted by 
Herrick (2) : “ I took several from which I broke off a leg ; placed them in 
one of the covered boats which fishermen call ‘ boutiques,’ in which they 
keep fish alive. As I did not allow them any food, I had reason to suppose 
that a reproduction would occur in them like that which I had attempted 
to prove. My expectation was not in vain. At the end of some months 
I saw, and this wfithout surprise, since I had expected it, — I saw, I say, 
new legs which took the place of the old ones which I had removed ; 
except in size they were exactly like them : they had the same form in all 
their parts, the same joints, the same movements.” Reaumur explained the 
phenomenon by postulating the presence of eggs or limb-germs scattered 
throughout the appendage, showing that when the leg was lost the 
nutriment which normally went to the whole limb was now supplied 
to the egg, development thus taking place. Bonnet in 1775 used the 
same theory to explain the regeneration of new heads and tails in 
Lumbriculus. 
In 1871 Chantran (3) pointed out that regeneration in Crustacea varies 
according to season. He indicated (which Reaumur failed to do) that 
moults must intervene during the period of regeneration in order that 
perfect limbs may be formed. 
Herrick (2), writing in 1895, mentions the work of Brooks (12) (1887), and 
describes the process of regeneration in lobsters. He indicates the relation- 
ship between the age of the individual and the power of regeneration, and 
also takes note of the fact that the rate of growth varies much at different 
times within the moulting period. 
* Mr J. Peden carefully recorded dates of moulting in my absence and fed the animals 
regularly. I am therefore indebted to him. 
