ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



1059 



consists of a broad glass tube M, into wbicb is blown a thin tube L. 

 M L, placed in the water-tank, communicates through a hole in the 

 lid with the caoutchouc tube P L. The lower part of this glass 



Fig. 231 



Fig. 232. 



3 z 2 



