284 VARIATIOXS OF THE SPOROCTST IN SAPBOLEGNIA. 



Summary. 



1. Certain speeiw ol' iSaprole<jnia are known to show variations in sporocyst 

 formation and discbarge, wlien grown under cultural conditions. 



2. In the present investigation certain variations are recorded tor an undeter- 

 mined species of Saprolegnia growing under natural as well as cultural con- 

 ditions. Leptolegnia, Fytliiopsis and Achlya conditions occurred rarely, while 

 Dictyuchuf: and ApUuies conditions were found freipiently. These variations oc- 

 curred in botl? club-shaped and cylindrical sporocysts, but weie not observed 

 arising from resting sporocysts. 



3. The Bictyuchzis condition described here diti'ei-s from either of those described 

 by Leehmere and is held to be the true DictyiKhus condition. 



4. Composite sporocysts were observed, the most important of which combine 

 the features of Dictyuchus and Aplaiies. The name "Dictyii-Apla>ie$" is sug- 

 gested for these sporocysts. 



5. Evidence is given in favour of the suggestion that ttie Aplaneg condition has 

 arisen from the Dictyuchus condition, by failure of the protoplast to escape 

 from the germ-tube during its early growth. 



6. New sporocysts are frequently formed as lateral, basal brandies of old sporo- 

 cysts, owing to the blocking of the latter with empty cyst cases and germin- 

 ating spores. 



All Text-figures were made at table le\el, with Zeiss camera lucida and tube at 

 160 mm., Leitz objectives 3 and (i and oculars 2 and 4. 



