230 Barrett . — Development and Sexuality of some 
be the chromatin material, is present. In cases (Fig. 51) where the nucleolus 
is absent, the chromatin masses are more prominent. They apparently 
become elongated and not infrequently assume the condition seen in 
Fig. 54. The conditions illustrated in Figs. 52 and 53 are frequent. They 
resemble somewhat the synaptic knot of higher plants, but I do not believe 
that to be their nature. 
Following the condition seen in Fig. 54, the chromosomes become 
massed together into a large, deeply staining body from which the tips 
of the spindle appear to emerge. The poles finally extend to the nuclear 
membrane, which usually persists to the late metaphase or early anaphase. 
Figs. 55 and 56 show spindles in the metaphase with large un- 
differentiated chromatin masses. Figs. 57-62 show indications of individual 
chromosomes of a rounded or globular form, which, as nearly as I could 
determine, number six (Fig. 66). In Figs. 57 and 59-61 the chromosomes 
have evidently divided, while in Figs. 63 and 65 they are passing in mass 
to their respective poles of the spindle. The nuclear membrane has practi- 
cally disappeared. 
Figs. 67-73 represent succeeding conditions in the anaphase and telo- 
phase stages. The conditions represented in Figs. 69-73 are not uncommon, 
especially in the sexual elements. Similar stages in dividing nuclei have 
been illustrated for the rusts as well as for a few other Fungi. Fig. 73 repre- 
sents the still united daughter nuclei with their respective nuclear membranes 
partially formed. No indication of direct nuclear division was seen. 
Very commonly, if not in the majority of cases, the nuclear spindle was 
more or less bent (Figs. 55-7, 60, 61, and 65). In every case of this kind 
the poles of the spindle were in contact with the ends of the oval or 
elliptically shaped nuclear membrane. There was no indication of centro- 
somes or any structure which would suggest nuclear polarity. 
4. Description of Species. 
In 1872 Cornu (5) described a species of Olpidiopsis to which he 
applied the name O. Saprolegniae. He was unable to determine whether 
or not it was the same form observed by A. Braun, but as he wished to 
preserve Braun’s specific name he used it for his species. 
In the description of this species Cornu specifically states that the 
resting sporangia are provided with a large number of very small spines, 
and are accompanied by an adjacent cell with a smooth wall. He further 
states : ‘ It is solely upon that species that the name O. Saprolegniae is 
to be applied. The form of the sporangia, however variable in the species 
of that group, is not necessarily spherical. The character of the species 
is not drawn from that, but from the presence of a smooth adjacent cell, 
coupled with an oospore provided with a large number of spines, isolated 
and not formed by ridges.’ 
