TRANSACTIONS OF SECTION K. 679 
certain points, due, perhaps, to their increased size, brought about by the 
vacuolisation. These telophase chromosomes become arranged into a spirem, 
as usually described, before the formation of the complete nuclear reticulum. 
The progressive vacuolisation continues until each chromosome becomes very 
much enlarged. The vacuoles, which are of various shapes and sizes, seem 
to run into each other laterally, thus forming eventually a reticulum from 
each chromosome. It appears as though certain portions of each chromo- 
some were being dissolved and replaced by a liquid substance, leaving a 
true reticulum. I believe that each chromosome is composed of chromatic 
granules, closely massed in a linin substratum. By means of the progressive 
vacuolisation these chromatic granules are separated. Not all of the linin 
disappears in this process, so that a reticulum of linin supporting the chro- 
matic granules remains. The whole process, so far as I have been able to 
observe, never begins from the outside, but is always internal. I have never 
found the lateral anastomoses of marginal portions, described by Grégoire, 
in well-fixed preparations. I have followed each chromosome to complete 
reticulation, and discovered traces of each chromosome in the resting 
nucleus. It does not appear as though the individual chromosomes anasto- 
mose with each other. I consider the resting reticulum as being composed 
of several independent elementary reticula, formed from the chromosomes 
as I have described above. 
During the early prophases the reticulum becomes more dense and more 
chromatic in appearance. Each chromosome becomes more condensed and 
distinct, resembling those found in the reconstruction stages. The vacuoles 
become fewer, and the chromatic portions larger and closer together. The 
chromosomes thus condensing are arranged into a ribbon or spirem, which 
is not, however, continuously chromatic, but consists of the individual 
condensed chromosomes united serially by less stainable achromatic portions. 
This ribbon, which is at first broad and reticulate, becomes densely chro- 
matic, and very thin and long, with chromatic bodies, which are apparently 
chromomeres. The ribbon splits lengthwise, while still very long and 
spirally coiled in the nuclear cavity. The spindle stages follow the usual 
descriptions. 
Although some authors, as Tellyesniczky and Fick, dispute the indi- 
viduality of the chromosomes, many investigators maintain that the indi- 
vidual chromosomes persist in a somewhat modified form in the resting 
reticulum. My results support this latter view. Although I have been 
unable to trace each chromatic granule throughout the various nuclear 
changes, I regard them as autonomous bodies. The existence of a regular 
reticulum, composed of chromatic portions united by linin strands, and the 
appearance of nuclear regions, which correspond to the reticulated chromo- 
somes, support this view. Since the same chromatic bodies, from which the 
chromosomes form the reticulum, re-enter the same chromosomes, the 
chromosomes themselves not only persist as individuals, but are apparently 
composed of autonomous granules. 
5. The Nuclear Phenomena of Ascomycetes in relation to Heredity. 
By Miss H. C. I. Fraser, D.Sc. 
In the majority of Ascomycetes investigated fertilisation involves the 
fusion in pairs of several nuclei. In normal cases one member of each pair 
is derived from an antheridium, the other from an ascogonium. In various 
degenerate forms the antheridium is wanting and the ascogonial nuclei fuse 
one with another, or in the absence of the ascogonium also, vegetative nuclei 
unite. Fertilisation, whether normal or degenerate, is followed by another 
fusion of two nuclei in the young ascus. 
