Spirogyra 89 
cated conjugation in Spirogyra than the one referred to in the paper 
above mentioned. This material formed a sort of net on the water. 
When examined it showed not only some further examples of the devi- 
ations in conjugation mentioned in the paper just cited, but also a few 
more complicated cases of what I term net conjugation on account of 
several filaments being held together in the process. Being associated 
often in such dense masses, it is really not so surprising that such 
examples of conjugation would occur, but rather we should have the 
right to expect that it would be more frequent than has heretofore 
been reported. Figure 1 gives a picture of one case. This figure is a 
camera drawing and, as will be seen, four filaments are concerned in 
the process. 
Another deviation from the ordinary is shown by Fig. 2. This 
is also a camera drawing. The material was obtained from the same 
place as that from which Fig. 1 was made. Most of the Spirogyra in 
the water where this material was obtained was Spirogyra elongata, 
but there was also a considerable quantity of Spirogyra communis and 
Spirogyra crassa. In a few instances some cells were observed where 
the number of chloroplasts varied. As shown in Fig. 2, a few of the 
cells had two chloroplasts, whereas the usual number of chloroplasts 
is one. 
