2250 



Journal of Applied Microscopy 



number of specimens will, however, be taken by means of a dip-net as they come 

 to the surface for air or swim across the pool in search of a means of exit. In 

 pools in honeycombed coral rock or other tunneled material, often the most 

 fruitful time is just as the tide begins to enter and force the poisoned water into 

 the tunnels. 



While possibly possessing no superiority over calcium chloride for this pur- 

 pose, it is worthy of note as an additional agent at the disposal of the collector. 

 U. S. Fish Commission, San Francisco. F. M. CHAMBERLAIN. 



A Method for Raising Coleochaete. 



One of the greatest diflficulties to be overcome in the laboratory is found in 

 trying to obtain cultures of some of the algae. 



For a number of years we were unable to secure a culture of Coleochaete. 

 However, in September of 1899, in making our collection of algae for winter 

 use, material gathered from a small pond in the vicinity was placed in a battery 

 jar of hydrant water. The mouth of the jar was covered with a glass plate and 

 sealed with vaseline. The jar was then placed in a south window. 



Coleochaete orbicularis. Camera lucida drawing. 



At different times during the winter various forms of alga were found grow- 

 ing in the culture. In the latter part of March the Coleochaete orbicularis was 

 discovered to be growing in great abundance around on the inside of the jar. 



This last fall a culture of Zygnema was taken from a pond and placed in an 

 open jar of hydrant water. The Zygnema degenerated, but by the last of March, 

 as in 1899, the Coleochaete orbicularis appeared in large numbers, and the indi- 

 vidual plants were larger in size than those of the previous culture. 



Judging from these two results it seems probable that Coleochaete may be 

 obtained for laboratory work by this method. Mary Avis Hickman. 



Biological Laboratory of De Pauw University. 



