MUNSON: SPERMATOGENESIS OF PAPILIO. 
61 
scribed above, are numerous chains of cylindrical cells placed end to 
end, the terminal one being spherical (pi. 12, fig. 5, st. c .; pi. 15, fig. 
68). They are not visible in the testes of the larya or pupa. They 
seem to develop late in the season, for they are seen only in the older 
forms. It may be that these chains are only empty spermatocysts 
remaining temporarily after the spermatozoa have been discharged. 
Yet for reasons which the following description will make clear, I 
have not been able to satisfy myself that this is the true explanation 
of them. 
The large terminal cell, which I at first thought to represent the 
head nurse-cell of a spermatocyst, is spherical (pi. 12, fig. 5, st. c.). 
Their size varies somewhat but they are the largest cells in the testis, 
larger even than the grandmother stem cell to be described presently. 
I have found no reference to these stalked cells in literature. They 
have a large spherical, though often irregular nucleus not especially 
rich in chromatin. The nucleus is usually located about midway 
between the center of the cell and its periphery. There is a distinct 
nuclear reticulum with stainable bodies at the nodes. These stainable 
bodies are sometimes aggregated into an irregular mass at one point. 
There are often, also, one or two paler bodies, probably representing 
nucleoli (pi. 15, figs. 68, 69, 77). 
The cytoplasm is slightly granular, and a cytoreticulum is visible, 
but not always ecpially distinct. In the center of the cytoplasm, 
there is a spherical body having the appearance of archoplasm with 
a central condensed portion containing a granule. That a relation 
exists between this attraction sphere and the nucleus is suggested by 
figures 68, 77 (pi. 15) where the nucleus is indented on the side facing 
the sphere. The body is also surrounded by zones which are in rela¬ 
tion with the nucleus (pi. 15, fig. 68). I am forcibly reminded, in 
this case, of the cytocenter and the cytocoel of the ovarian egg of 
Clemmys (Munson, ’ 04 ). 
Occasionally similar cells are found free in the fluids of the follicle 
(pi. 12, fig. 5, a-). In plate 15, figure 69, is represented such a free cell. 
Besides the nucleus and sphere which in this case are near the center, 
there are in the cytoplasm several irregular bodies resembling the 
yolk nucleus of the tortoise egg. In fact, these cells resemble eggs 
very elosely. In figure 83 (pi. 15) another such free cell is represented, 
having a more distinct cytoreticulum and likewise a spherical body 
near the nucleus. Two large vacuoles partly surround it. Figure 
