539 
Cytology of the A sens. 
In several of the divisions observed in Humarici granulata an elongated, 
deeply staining body is present (Figs. 8, 10) extending from the group 
of chromosomes to the nucleolus or to one of the larger of the granules 
which lie around the nuclear area. The appearance suggests that stainable 
material is passing towards the chromosomes from the nucleolus, and the 
irregular or vacuolate character of the latter (Fig. 8) is frequently in 
keeping with such an inference. Spore-formation was not studied in detail 
in Humaria granulata, but such observations as we have made accord well 
with the description given of this process in Lachnea ster corea. 
Ascobolus furfuraceus. 
Nuclear fusion was observed by E. J. Welsford ( 19 ) in 1907 in the 
ascogenous cell of this species. In the same year the ascus was studied by 
Dangeard ( 4 ), who described eight chromosomes in the first mitosis, and 
four in the two which succeed it. When the latter account came to our 
notice our work on Ascobolus furfuraceus was already begun, and we are 
now able to confirm Dangeard’s observations. 
The heterotype prophases are here well marked, and it is possible 
to recognize the synaptic stage (Fig. 15), the double spireme (Fig. 17), and 
the characteristic forms of the gemini (Fig. 19). Chromosome-formation is 
preceded by an arrangement of the spireme into loops (Fig. 18) correspond- 
ing to the second contraction phase of other forms. 
Eight chromosomes are present in the first mitosis (Figs. 20, 22) and 
four throughout the second and third (Figs. 25, 26, 29, 30). The pairing of 
the chromosomes which are to pass to different nuclei in brachymeiosis thus 
takes place, as in Humaria granulata , at an early stage. In Peziza vesicu- 
losa (8), another species in which the reduced number of chromosomes 
is apparent on the homotype spindle, a contraction stage was recognized 
both in the second and third prophase. This was regarded as representing 
the moment of association of the allelomorphs, and it was suggested that 
their union did not endure through the resting-stage, since a contraction 
(and presumably a pairing of the chromosomes) took place in the third 
as well as in the second prophase. In Ascobolus furfuraceus the prophases 
of the third division are readily studied, and it appears to us that here also 
the stages represented in Figs. 27 and 28 are best compared to the so-called 
first contraction of meiosis. 
In the majority of Discomycetes examined, either in the course of this 
investigation or previously, the nuclear area is well marked, and is bounded, 
of chromosomes in the later divisions in the ascus is at least as well authenticated as the chromo- 
some number in the smaller nuclei of the ascogenous hyphae. There thus remains a fusion in the 
ascus and a brachymeiotic reduction, the latter a process nowhere associated with sexual fusion. 
If this be the case our present specimens of H. granulata have progressed a stage further than other 
investigated forms in the loss of a sexual process. 
