ditions for growth have been favorable, it is seen that a 
zoospores ae escaped, becomes protruded a as a 2 pila by 
further erwin of which the second sporangi 
| This 
; the o original one ( fig. 17). ‘They all. dehisce at the same 
though : 
1902] CLADOCHYTRIUM ALISMATIS 55 
gelatinization forms a distinct hyaline area extending inward in 
a manner similar to that already described in connection with the 
germination of the resting sporangia (fig. 72). At the time of 
dehiscence this gelatinized envelope is often protruded at the 
opening. Into this vesicle the zoospores dart, forming a ball, 
though it becomes dissolved and the zoospores scattered before 
all have escaped. The number of the zoospores that is produced 
depends on the size of the sporangium and varies from three or 
four up to probably as many hundred. The zoospores are like 
those formed in the resting sporangia except that they are pos- 
sibly somewhat smaller. They settle down on the leaf in time, 
and give rise to secondary temporary sporangia, and even a third 
generation has been observed on the same leaf. Because of 
their crowded condition, the failing power of the leaf to furnish 
nourishment and its diseased condition, these second and third 
generations, at least in cell cultures, often produced sporangia 
of smaller size, and their zoospores seemed less active, in 
extreme cases even failing to move around after being dis- _ 
charged. Sometimes such zoospores had oil drops of a sickly — 
reddish-yellow color. In leaves kept in cultures for some time, 
occasionally there occurred areas in which the spernely covered 
halt the surface of the leaf (fig. 20). 
er a sporangium has discharged its zoospores, if a come 
stages in the devel 
given zoospore de 
this ‘Place of discharge | often” becomes 
