280 



VARIATIONS OF THE SPOROCY><T IX SAPROLEGXIA, 



Also, "The zoospores were observed lea\iug their cyst walls ami escaping through 

 the tubular process, pushing before them the empty cyst cases which were in the 

 tube/'t Leehmere only observed this condition during the development of rest- 

 ing sporocysts in white of egg cultures. It is interesting to note that here the 

 second motile phase commences within the sporocyst. A further Dietyuclnts con- 

 dition is recorded by Lechmere in his second paper.J He says of these sporo- 

 cysts : "they are always derived from gemmae, and in shajje they are broad and 

 short. The empt> spore eases form a dense network within the sporocyst, the 

 wall of which is very thin and is apparently directly penetrated by the zoospores 

 on their escape froiii their encysted condition." 



The Dictyuchus condition observed by the writer, resembles the second of 

 Lechmere's Dictyuchus forms in the fact that the- second motile phase occurs out- 

 side the sporocyst, the first being suppressed. The sporocysts are found to be 

 either short and club-shaped, or long and cylindrical; they are never observed to 

 arise from resting sjjorocysts and occur freely under natural as well as cultural 

 conditions. The encysted spores send out a protuberance which penetrates the 

 sporocyst wall and projects for a distance of varying length (Text-fig. 3). The 

 protoplast then shrinks from the cyst wall, streams out through the cyst tube, the 



Te.xt-tii^.S. Portion of younj; J)iclyi(c/ius sporocyst. Note germiiiiition of encysted 

 spores and passing of protoplast through cyst tube. (.\ 2:iO) . 



Text-figs. 46. k 'la. Club-shaped /-'/V/,l7«7;ft.s' sporocyst show-ing liberation af ciliated 

 zoospore and the coming to rest and second encystinent of tlie latter, (x 2;iO). 



tip of wliich degenerates. A ciliated zoospore is liberated which reuuiins at- 

 tached to the cyst tube for about five minutes, maintaining a rocking motion. It 

 then swims away and comes to rest close to the sporocyst after a period of from 

 3 — 5 minutes (Text-figs. Ah and 4«.). Tliis motility is noticeably feelile in com- 

 parison with the vigorous motility in Lechmere's first Dicttiuclius condition where 

 the zoospores push (lieir eiiii>ty cyst cases l)e1'orc them wlieii leaving the sporo- 



ifd., ix., 1910, p.:il7. 



:/(/., X., 1911, p.l8(i, fig. 17. 



