REPORT OF COMMISSIOXKRS OF IXLAXD FISHERIES. 83 



tain kinds of fresh water worms could be cut into as many as four- 

 teen pieces and still each piece would reproduce a new worm having 

 a new head and tail. Trembley spilt a hydra's head and obtained a 

 double-headed hydra. Indeed, he succeeded by this way in getting 

 even an eight-headed hydra. Spallanzani discovered that a tadpole 

 could reproduce a new tail; that salamanders could renew both tail 

 and legs; that slugs could regenerate a new head. The celebrated 

 experiments of these naturalists aroused a widespread interest in 

 the subject of regeneration, which at the present day is growing with 

 increasing momentum. 



Numerous investigators have entered this promising field and are 

 expanding its boundaries in many directions. While a review of 

 their experiments and results on a great variety of forms in both 

 animal and plant life would be irrelevant to our present purpose, per- 

 haps a brief sketch of the work which has been done in the crustacean 

 group and some of the theories of regeneration will be of value in in- 

 dicating a few of the lines of interest in our present problem. 



Among the investigators who have studied the regeneration of lost 

 appendages in Crustacea are Reamur, 1712; Goodsir, 1844; Chantran, 

 1873; Brooks, 1873; Herrick, 1895; Herbst, 1896-1901; Miss M. I. 

 Steele, 1904; and Morgan, 1898-1905. 



Reamur began his experiments on crabs and lobsters, but the sea 

 broke over and carried away his boxes or filled them with sand. He 

 then experimented with crayfish. The following description in his 

 own words is one of the earliest accounts of experiments with cray- 

 fish: "I took several of them from which I broke off a leg; I placed 

 them in one of the covered boats which the fishermen call 'Bon- 

 tiques,' 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 expectations 

 were in not vain. At the end of some months I saw, and this without 

 surprise, since I had expected it — I saw, I say, new limbs which 

 took the place of the old ones which I had removed. They had the 

 same form in all their parts, the same joints, the same movements. 



