212 BOTANICAL GAZETTE [MARCH 
absence in all of the preparations. Since R. undulata is an uncom- 
mon species, it is infrequently collected, and the writer, desirous 
of supplementing his material with preparations showing mitosis, 
searched for the fungus without success throughout the summers 
of 1915 and 1916. While unwilling to state that conjugate divi- 
sions do not take place in the ascogenous hyphae of this species, he 
has been unable to demonstrate their occurrence. On the other 
hand, a periodicity in mitosis which would constitute a more or 
less simultaneous division of all the nuclei in the archicarp might 
easily give at the rounding up of the daughter nuclei a marked 
appearance of pairing. The pairs of nuclei in the ascogenous 
hyphae could also originate in the same manner. Until mitotic 
figures, either of simple or conjugate divisions, have been demon- 
strated in the ascogenous hyphae, it will be well to reserve judgment 
' as to the meaning of the paired condition. 
A comparison of our work on R. undulata with that of other 
investigators who have studied the origin of the paired condition 
in those Ascomycetes in which a male organ is lacking or non- 
functional is not enlightening. Although great variation exists 
- in their accounts, fusion of nuclei in pairs in the ascogonial cells is 
described as occurring in Lachnea cretea (FRASER 30), Ascophanus 
carneus (CUTTING 18), and Thecotheus Pelletieri (OVERTON 56). 
Conjugate divisions have not been described in any case. CLAUSSEN 
(17) alone in Pyronema confluens has figured conjugate divisions in 
the undifferentiated portions of the ascogenous hyphae of the Dis- 
comycetes. 
The ascogenous hyphae of R. undulata undergo repeated branch- 
ing as they approach the hymenium. They soon become multi- 
septate (fig. 12), the individual cells containing a varying number of 
nuclei which are usually, though not constantly, in evident pairs. 
On the transverse septa are found deeply staining granules resem- 
bling those in the vegetative hyphae. In some cases these are 
aggregated into large granules similar to the deeply staining pads of 
the archicarp, but they are in reality much smaller. Other granules 
occur throughout the cytoplasm. No open pores in the septa 
have been demonstrated, and although it is possible that minute 
protoplasmic connections exist, there is no reason to think that 
nuclei migrate from cell to cell. In later stages the deeper lying 
