_ e] THE COMPOUND OOSPHERE OF ALBUGO BLITI 227 
q further. The mature endospore consists of two layers that may 
_ tecalled the primary and secondary endospores according to | 
their development. The primary endospore appears as an even 
ayer lining the primitive wall, at first agreeing precisely in stain 
_ faction with the gelatinous material of the vacuoles, which is 
Still present (fig. 93). The primary endospore, however, soon 
_ Wtluses this stain and gives the reaction of cellulose with chlor- 
4 iodide of zinc. A variation in the normal sequence was found in 
_ M€oospore in that the epispore was completed before any trace 
_ Of endospore was to be seen. 
j The conspicuous feature of the third period is the laying down 
_ ofthe secondary endospore inside of the first. It is of cellulose, 
and is about equal to the primary endospore in thickness. The 
q Wo layers of the fully developed endospore are clearly evident 
; when stained, also when they cleave apart in a perfectly regular 
mtd as they frequently do ( fig. 97). There seems to be a 
__ Pase in the laying down of cellulose when the primary endospore 
3 “completed, as is shown by the fact that perceptible changes 
| Sur in the development of the epispore after the first and 
E belore the second endospore is formed. Fig. 94 shows the 
4 — trace of the secondary endospore that was seen. When 
_ “second layer of cellulose is completed the gelatinous material 
: completely disappeared from the vacuoles. The fact that 
this 
Substance appears just before the laying down of the primary 
oo young, and the disappearance of all of the gelatinous 
“multaneously with the completion of the secondary 
a significant facts, They indicate that this substance 
Of the , Y connected with the formation of the cellulose walls 
ees to the a ppears to be transferred directly from the 
Re cellulose. exterior of the protoplasm, there to change to 
ol iia food substances accumulate in the center of 
Wotie 5 taking the form of one very large irregularly shaped 
Mtaining ie Around this mass lies a zone of cylopaee 
: © fusion-nuclei in resting condition. Their number 
