THE DEVELOPMENT OF THE SPORES IN PLEURAGE 
ZY GOSPORA 
I. M. Lewis 
(WITH PLATE XIX) 
Pleurage zygospora (Speg.) Kuntze, formerly reported from Italy 
alone, has been shown by the cultural methods employed by 
THAXTER and later by GrirFirus' to occur throughout this country. 
This species was first described by SPEGAzzINr in 1878, and was 
Placed in Sordaria as S. zygospora. It was later transferred from 
this genus by Saccarpo? and placed in Philocopra. This transfer 
was made on the basis of the apparent number of spores being 16 
in place of 8. Later (1898) Kuntze‘ described it as a Pleurage. 
This classification was retained by GrirFiTHs in his memoir. The 
species name zygospora has been retained throughout. 
he position of this species depends upon the interpretation 
which is placed upon the mature ascospore. It is obvious that 
such an interpretation should be based upon a knowledge of the 
development of the spore. A cytological study of the peculiar 
appendaged condition of the spores in the genus Pleurage has not, 
so far as the writer is aware, been carefully made. A complete 
understanding of the nature of the primary appendages necessarily 
involves a study of the behavior of the nucleus of the primary 
Sporogenous cell. This detail was not attempted by GRIFFITHS 
in his memoir on the Sordariaceae. 
The spores of the species of this genus in which the primary 
appendage occurs are known to pass through a peculiar mode of 
development. The primary sporogenous cell is cut out of the cyto- 
plasm of the ascus after the method described by HaRPER.S These 
* Grirritas, D. A., The North American Sordariaceae. Mem. Torr. Bot. Club 
TI:I-134. gor. 
* SpeGazzint, C., Michelia 1:227. 1878. 
’Saccarpo, P. A., Sylloge Fungorum 1:251. 1882. 
* Kuntze, Orro, Revisio Generum Plantarum 3:505. 1898. 
5 Harper, R. A., Annals of Botany 132507. 1899. 
369] [Botanical Gazette, vol. 51 
