244 Carr withers . — Contributions to the Cytology of 
the vegetative and the fertile hyphae (Figs. 3, 4, 5, 6). The former show 
structures which have every appearance of spindles, with two chromosomes 
(Figs. 3, 4) ; the latter have four chromosomes (Fig. 5), and at a later stage 
eight are visible (Fig. 6). The nuclei are, however, so minute that it would 
be unwise to attach any great importance to these phenomena. It is con- 
ceivable that the ‘ spindles ’ are only a fibrillar arrangement of the cytoplasm, 
and the ‘ chromosomes ’ nothing more than some of the granules which are 
abundant in the hypothecial tissue. It is difficult to account for the occur- 
rence of a bent hypha with two spindles, each bearing four chromosomes 
(Fig. 5), on the basis of coincidence, and it seems desirable to give the 
evidence for what it is worth, without accentuating its theoretical importance. 
The ascogenous hypha bends over to form the characteristic crozier, 
and two nuclei pass into the bent portion ; these divide simultaneously, 
and eventually a terminal uninucleate and a penultimate binucleate cell are 
cut off (Fig. 7). There is some evidence to show that the nucleolus of each 
nucleus now buds off a portion of itself, which is extruded at one end of the 
nucleus and is very conspicuous at this stage (Fig. 8). 
The two nuclei of the penultimate cell fuse, and the nucleolar granules 
remain one at either pole of the resulting nucleus (Fig. 8). A projection is 
formed from the penultimate cell, and into this the large double nucleus 
passes ; it grows rapidly, pushing up among the paraphyses, and forms the 
young ascus. The terminal cell often fuses with the stalk cell, their nuclei 
unite, and a second ascus is formed (Figs. 9, 10). 
Meiosis. 
The nucleus of the young ascus presents a characteristic double appear- 
ance. It is oval in shape, and at either pole is visible the granule which was 
extruded after budding off from the nucleolus. Shortly after fusion the 
chromatin contracts into two close masses, one at either end, and the 
granules, which have hitherto stained with nucleolar dyes, gradually become 
impregnated with chromatin (Fig. 12). 
As contraction passes off the chromatic granules are expelled from the 
nucleus (Fig. 13), forming deeply staining pear-shaped bodies which maybe 
seen traversing the nuclear membrane (Figs. 14, 15). In nearly all cases the 
original granules appear to be extruded, but there are also smaller chromatin 
bodies which are budded off directly from the chromatic substance of the 
nucleus. The larger bodies are evidently expelled with some force, leaving 
behind them a clear track in the cytoplasm (Fig. 14). At a somewhat later 
stage secondary buds may be formed from the nucleolus (Fig. 16), but their 
further history was not traced. The extruded bodies gradually degenerate 
and once more take up nucleolar stains, until finally they are visible only as 
refractive granules, which at this stage adhere closely to the nuclear 
membrane (Fig. 20). 
