Methods of Reproduction in the Saprolegniacece. 201 
The occurrence of oocysts in rows may be looked upon as a 
consequence of the germination of the various rows of chain gemmae 
from which they were invariably formed. 
As regards the duration of the resting period, much stress 
cannot be put on this point, which shows such great variation in all 
the species and must necessarily depend to a great extent upon 
external conditions. 
The last point of difference must be regarded as a special 
variation rather than as showing any specific distinction. 
Conclusion. 
Upon the following general characters shown by Species II., I 
then base my decision for determining this species as that of S. 
Thureti, de Bary, 1881. (Synon. 5. ferax (Gruith) Thuret, 1850). 
1. Stout hyphse (30—40 jj) on the young mycelia becoming 
more lax during oocyst formation. 
2. Elongated cylindrical sporocysts of different lengths, 
often only slightly wider than the hyphae. 
3. The repeated upgrowth of the hypha within the dis¬ 
charged sporocyst. (This process being capable of 
many variations). 
4. The presence of cylindrical oocysts with the oospores 
in a row. 
5. Shape and size of the ordinary oocysts. 
6. The presence of specially small oocysts containing a 
single oospore. 
7. The numbers of the oospores, 6—12. 
8. The diameter of the oospores, 22—27/^. 
9. The entire absence of antheridial filaments and 
antherocysts. 
Summary. 
As the result of the investigation of Species I., the following 
facts have been established:— 
1. It is identical with the species described previously 
(New Phyt., Vol. IX.), but not named specifically. 
2. Owing to the formation of sexual organs of repro¬ 
duction, as well as the various asexual methods, 
the species has been established as that of X. torulosa, 
de Bary. 
