jf 
ryjtt] LEWIS—SPORES IN PLEURAGE 373 
jh a long multicellular sterile portion which eventually disappears. 
_ The basis of the structure and origin of the spores seems to me 
to be the proper basis for their definition. I regard this species, 
therefore, as eight-spored, and the classification of KUNTZE as the 
proper one. 
The question concerning the probable significance of the two 
types of spores produced, while interesting, must remain more 
or less speculative. It seems probable that this condition must 
have been derived from ancestors which produced multicellular 
spores, and that the production of fertile and sterile cells is due to 
specialization and sterilization. The first step in this process might 
have consisted in the formation of the enlarged fertile cells, follow- 
ing which the connecting cells ceased to be functional. The loss 
of cross-walls and the consequent production of the unicellular 
appendaged type of spore, characteristic of this and other members 
of the Sordariaceae, could easily follow. 
UnIversity or TEXaAs 
AUSTIN 
EXPLANATION OF PLATE XIX 
All figures were drawn from sections with the aid of a camera lucida, a 
Leitz :y oil immersion lens, and ocular no. 1, and are magnified 880 times. 
IGS. 1-3.—Young asci showing relatively large nuclei and rather dense 
cytoplasm. 
Fic. 4.—Ascus about two-thirds mature size, with vacuolate epiplasm and 
8 primary sporogenous cells. 
Fic. 5—Various stages in the growth of the spore filament. 
Fic. 6—Young spores showing the crescentic shape and with several 
nuclei; the ascus has not increased much in 
Fro. 7-—Spore filaments of the sana tos ; the spores are almost as 
long as the ascus, but the end portions have not — to increase in size; 
this same appearance prevails in the other type of spo 
Fic. 8—A later stage than fig. 7; some of the at are abortive, a con- 
dition which frequently occurs. . 
IG. 9.—Older stage of the same type of spore shown in fig. 8, with the 
ends becoming enlarged. 
Fic. 10.—The unicellular type, showing the multinucleate condition and 
enlarged ends, each containing a single nucleus. 
Fic. 11.—Mature spores of the type shown in fig. 10; secondary appendages 
derived from the epiplasm are shown. 
Fic. 12.—Mature spore of the three-celled type. 
