REGENERATION IN THE CRAYFISH * 
BY JOHN J. LAMBERT. 
In working over a series of crayfishes for class purposes, 
certain quite suggestive facts came to light concerning the 
regeneration of the appendages under the conditions of 
normal environment. The specimens examined were 
mature males and females taken directly from their natural 
surroundings. While not imputing lack of value to experi- 
mental work in the field of regeneration, it certainly is 
true that nature and the laboratory are two very different 
things. It is therefore felt that the following notes, while 
preliminary in character, are of sufficient value for pub- 
lication. 
One hundred and forty individuals were examined, fifty- 
five of which were females, eighty-five males. Of this 
number twenty females and twenty-eight males, forty- 
eight in all, had one or more appendages wanting. 
The following chart was prepared to set forth these facts 
in a concise and systematic way. While it may not give 
as much as would be desirable, still the main suggestive 
points are indicated. 
* From the Laboratory of Animal Morphology, State University of Iowa, Gilbert L. 
Houser, Director. 
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