402 Wm. s. Marshall and C. T. Vorhies, 



a long thread-like portion. This and the preceding figures illustrate 

 a type of cell in which the nucleus occupies a somewhat smaller 

 amount of space than do the following ones, the branches being more 

 widely separated. We do not wish it understood however, that nuclei 

 of this type must have a position anterior or posterior to that part 

 of the gland which is widest. On the contrary, very complex nuclei 

 which seem to fill a much larger amount of space, relatively, may be 

 found alternating with less complex ones in which cytoplasmic areas 

 predominate. 



In many cells the nucleus appears quite similar in all its parts; 

 in others, however, two quite difierent portions may be noticed, each 

 of which is limited to one definite area of the cell, although they 

 gradually pass, in the central portion of the nucleus, into each other. 

 Nuclei of the latter type are shown in Figs. 5 and 6, In these a por- 

 tion, consisting of broad branches, may be distinguished from another 

 part in which all the ramifications are more slender and show more 

 pronounced differences in width. 



Figure 6 shows a nucleus, part of which is very similar in struc- 

 ture to those described and figured by Gilson [4] for Phryganids. He 

 has described the nuclei as being segmented, with the segments drawn 

 out into long threads and entirely separated from the main portion. 

 A careful study of the apparently segmented part of this nucleus 

 (Fig. 7) shows that the seemingly detached pieces are always connec- 

 ted to the main part of the nucleus. It is also reasonably certain 

 that no anastomoses occur, although the attenuated branches may 

 overlap in a complicated manner. This interesting portion of the 

 nucleus we have represented in greater detail (Fig. 7). In a number 

 of nuclei we found points where it was difficult or impossible to ascer- 

 tain that anastomoses did not occur. Having in so many nuclei found 

 the opposite to be true (the more careful the study with a high 

 power of the microscope the fewer the anastomoses become), we feel 

 justified in asserting that branches seldom or never connect. The great 

 thickness of the cytoplasm covering the nuclei and the difficulty of 

 getting perfect stains make an absolute determination in m'àiìj instances 

 very difficult. 



