Thaxter , on Chillies ( Capsicum spp.). 401 
colour of the sporangia is due to the enclosed mass of brown spores. 
The sporangia vary a great deal in diameter, but usually they measure 
between 47*6 and 170^. The spores are of the same colour as the conidia, 
and they are of about the same size (16*5-24 x 7*7-11 fx), but the epispore is 
thicker and not striated. The spores have no hyaline appendage at the 
base, but they have a cluster of fine cilia at both ends (Fig. 6). They are 
equilateral, rarely three-cornered. 
The spores germinate in the same way as do the conidia. 
Chlamy do spores . In cultures the hyphae at times develop intercalary 
vesicles. The vesicular walls either remain unthickened or, as in true 
chlamydospores, become thickened. The chlamydospores are highly 
vacuolar. Germinating spores also develop chlamydospores (Fig. 4). 
Zygospores. The development of the sexual fructification of certain 
algae and aquatic fungi depends, according to Klebs, 1 primarily upon factors 
of nutrition and environment. Kauffmann 2 has found that the formation of 
oospores of some Saprolegnia can be influenced by definite chemical and 
physical conditions which can be readily controlled. Shear and Wood 3 
believe that the perithecial-forming faculty in the numerous cases of Glome- 
rella , studied by them, is evidently a fairly well fixed hereditary racial 
character, because if once a race or strain which produces perithecia in 
culture media is obtained other generations grown from this race or strain 
continues to produce perithecia indefinitely. Pethybridge and Murphy 4 
have found the same racial hereditary character in the formation of the 
oospores of Phytophthora infestans ; but in Phytophthora parasitica the 
author 5 has found that the oospore-producing faculty is an hereditary 
racial character only if each generation of the oospore-forming strain is 
grown on a medium different from the one on which the immediate parent 
was cultivated. But the- formation of zygospores of the chilli Choanephora 
does not depend on the development of a strain which would in subsequent 
subcultures continue to give the sexual spores, nor upon other conditions 
mentioned above, but, curiously enough, the zygospores of this Choane- 
phora are developed in cultures only when the mycelium arises from conidia 
taken directly from the host plant and not from the fungus growing on 
nutrient medium. This peculiarity in the production of zygospores has 
been observed by Wolf. The development of the sexual spores (Figs. 7-9) 
is similar to that of C. infundibulifera and C. cucurbitarum . The zygo- 
1 Klebs, G. : Die Bedingungen der Fortpflanzung bei einigen Algen und Pilzen, 1896. 
2 Kauffmann, C. H. : A Contribution to the Physiology of the-Saprolegniaceae, with Special 
Reference to the Variations of the Sexual Organs. Ann. Bot., xxii, 1908, p. 377. 
8 Shear, C. L., and Wood, A. K. : Studies of Fungous Parasites belonging to the Genus 
Glomerella. U.S. Dept, of Agric., Bur. of PI. Industry, Bui. No. 252, 1913, p. 72. 
4 Pethybridge, G. H., and Murphy, P. A. : On Pure Cultures of Ph. infestans , de Bary, and the 
Development of Oospores. Proc. Roy. Dub. Soc., xiii (N.S.), No. 36, 1913, p. 581. 
B Dastur, J. F. : On Phytophthora parasitica , nov. spec. Mem. Dept, of Agr. India, Bot. 
Ser., v, No. 4, 1913, p. 204. 
