5 
to be well worthy of further consideration. From observa- 
tions of the crawfish in captivity it appears that one male 
may attend several females during the season. This has 
been actually observed, and may further be rendered fairly 
certain from the fact that the female has been observed to 
extrude her ova only two or three days after copulation. 
It follows therefore that there is a much greater necessity for 
protecting the female than the male. 
(2) Stages in Life History of Crawfish.—It is of importance 
from a practical point of view to ascertain the form and 
habits of the young crawfish. We have found that the first 
stage after hatching is in the form of a small somewhat opaque 
form which swims rapidly to the surface of the water by means 
ofits antennae. It is then transformed into a flat transparent 
form which swims about by means of special swimming branches 
developed on the legs. It apparently then descends to the 
bottom of the sea and by a series of stages becomes larger. 
During this process it would appear to migrate to much 
deeper waters, as larger forms resembling the last mentioned 
are found there. We have been unable as yet however 
to be quite certain of this, as there are no adequate facilities 
for deep water trawling. With the means at disposal how- 
ever it has been possible to fish with a special trawl in fairly 
deep water from a motor boat. The continuation of this 
deep-sea work will probably clear up some points in the develop- 
ment and migratory movements of the young crawfish. 
The next stage which is undoubtedly a young crawfish is the 
‘puerulus”’ stage, which has hitherto only been found close 
inshore. Only a very few of these have been got, chiefly 
clinging to set nets when taken out of the water. 
As a result of recent investigations some further advance 
has been made in the elucidation of the life history of the 
crawfish, namely the discovery of the normal habitat of the 
‘“ puerulus ’ stage. These were found in the course of trawling 
' with the special net above mentioned. Specimens of this 
stage were found at the following dates and localities :— 
2/11/17 Between Breakwater and Green Point Light- 
house. | 
7/11/17 Between Breakwater and Green Point Light- 
house. 
4/12/17 Grainger Bay inside Breakwater. . 
5/12/17 Granger Bay inside Breakwater. 
Some of these were taken to the marine laboratory in the 
hopes that they might be kept alive till they reached the 
next stage in their development which was unknown. They 
proved to be fairly hardy animals, and, when placed ina specially 
arranged tank with a good supply of sea water, throve very 
well. The typical red spots of the puerulus stage gradually 
disappeared, and a dark olive brown began to appear under 
[C.P. 3—1918] 
