Reproduction of Cystopus Candidus, Ldv. 301 
spores are immediately placed is often only slightly raised 
and irregularly torn by their development, and its projecting 
torn fringe surrounds the group of spores as a sort of 
indusium. 
Leveille (’47) founded the genus Cystopus with the following 
characters Receptacle composed of very small irregular 
cells, forming a sort of disc covered with cylindrical vesicles, 
terminated by several spores arranged in a chain. The spores 
are spherical or cubical. The following species were placed 
in the genus - U redo Candida (Pers.), U. cubica (Mart.), 
U. Portidacae (D. C.), U. Bliti (Bivon.), U. floriformis 
(Merat), &c. 
Berkeley (’48) gave a short account of the structure of the 
mycelium and the sporangia of Cystopus candidus , illustrated 
by four figures, in which the moniliform character of the 
arrangement of the spores is described. This account was 
anticipated and confirmed by Leveille. 
L. R. Tulasne (’54) gave a description with figures of 
C. Portidacae , Lev. ( Uredo Portulacae , D. C.). The myce- 
lium is shortly described and its mode of ramification. 
The method of formation of the sporangia in C. Portulacae 
and C. candidus is described and good figures are given in 
PL VII, Figs. 1-5 of the appearance of the mycelium and 
spores of C. Portidacae. He states, however, that there are 
two kinds of spore developed in C. Portulacae — ( 1 ) shortly 
cylindrical spores, united into long chains, form the larger 
number; they have a smooth cell- wall and are sometimes 
nearly colourless, sometimes tinged with brown, and ( 2 ) spores 
with a spherical and trigonous form, larger, and tinged a 
yellowish brown which is always more or less deep. They are 
developed at the apex of the chain and are the first spores 
formed therefore. In C. candidus the spores are nearly always 
similar to one another, but sometimes one distinguishes larger 
ones with a manifestly three-sided form. The dimorphism 
which is very evident in C. Portulacae , is also present to a less 
degree in C. candidus. He was not able to confirm Prevost’s 
observations as to the zoospore formation, but states that 
