41 6 W el s ford . — Conjugate N tic lei in the Ascomycetes. 
nuclei, and the conjugate character is not well marked. As the reserve 
food of the conidium is used up the paired condition becomes still less 
evident. Fig. 3 shows an older and more starved hypha grown in very 
dilute turnip juice; in the second cell no indication can be seen of the 
nuclei being in pairs. 
A similar phenomenon has been found in the mycelium of Sclerotinia 
Libertiana . The nuclei in well-nourished hyphae growing in the stem 
of Vida Faba are arranged in pairs, whilst in starved hyphae the nuclei are 
unpaired. 
As pointed out by Fraser 1 in 1913, conjugate divisions are not at 
all uncommon in the different parts of the Ascomycetes. They have been 
observed by various writers : in the conidial mycelium of Hypomyces 
3 perniciosum (Massee) ; in the germ tubes of the ascospores of Ceratostoma 
Figs. 1-4. Conjugate nuclei in Botrytis cinerea. All figs, x 1200. 
brevirostra (Nichols) ; in the paraphyses of Helvetia crispa (Carruthers) ; in 
the large storage cells of Helvetia elastica (McCubbin) ; and in the ascogenous 
hyphae of a large number of Ascomycetes (Maire, Guillermond, Claussen, 
Faull, & c.). The presence of conjugate nuclei in the ascogenous hyphae 
has been very frequently noticed, and it has been regarded by certain 
authors (Guillermond, &c.) as a special sexual phenomenon. Both Claussen 2 
and Faull 3 lay great emphasis on this arrangement of the nuclei in the 
ascogenous hyphae, regarding the synkarion which they find there as 
consisting of a male and a female nucleus. Faull asserts that the ‘ conjugate 
1 Fraser, H. C. I. (Gwynne Vaughan) : Development of the Ascocarp of Lachnea Cretea. 
Ann. Bot., xxvii, T913, p. 559. Full references are given in this paper. 
2 Claussen, P. : Zur Entwicklungsgeschichte des Ascomyceten Pyronema conflnens. Zeit. f. 
Bot., iv, 1912, p. 1 . 
3 Faull, J. H. : The Cytology of Laboulbenia chactophora and Z. Gyrinidarum, Ann. Bot., 
xxvi, 1912, p. 325. 
