298 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 



the formation of zoospores the protoplasmic mass became 

 contracted towards the upper part of the sporangium, the 

 operculum was thrown of}', and the protoplasmic mass was 

 discharged as a rounded naked body, which in about fifteen 

 minutes becanje coated with a delicate cell-wall. The red 

 granules were first collected towards its centre, but were 

 subsequently equally distributed, and the protoplasm sub- 

 divided into individualised portions, each containing a 

 granule, and which were finally set free as rapidly moving 

 zoospores with a posterior cilium. The zoospores ceased to 

 move, became amoeboid, the cilium was drawn in, and the 

 zoospore in a few minutes began to germinate. This was 

 effected by its elongating into a tube, developing a foot at 

 one end and dichotomously branching at the other. Besides 

 the production of zoospores, zygospores, of a blood-red 

 colour, very thick-walled and covered by irregular protuber- 

 ances, were formed by the conjugation of two horizontal 

 lateral branches thrown out from the two ramifications of 

 the plant. These germinated very readily. 



A second nearly related form {Tetrachytrium triceps) was 

 found on various submerged objects, with cell-contents of a 

 greyish-blue. The stem-cell was also furnished with a foot, 

 and divided above into three branches, each bearing an oper- 

 culate zoosporangium, and beneath them an involuted " ap- 

 pendix." The zoosporangium discharged its protoplasmic 

 contents as before, but then separated into only four por- 

 tions, which were ultimately set free by the rupture of the 

 niother-ceil-wall, as four blue-coloured bodies with a median 

 clear spot. They did not exhibit any amoeboid movements 

 on coming to rest, but conjugated in pairs. Zoospores, which 

 were unable to conjugate, never germinated, but the zygo- 

 spores readily germinated, reproducing the plant with its 

 triple branches and " appendix." 



These two ofganisms appear to differ from Chytridiea, on 

 the one hand, in the presence of zygospores in Zygochytrium, 

 and the conjugation of the zoospores in Tetrachytrium. 

 The author considers that these new types may form a 

 special natural group, with Chytridiea, Ancylistece, Sapro- 

 legniea, Zygomycetes {Mucorini), and Peronosporece, for 

 which he proposes the name Siphomycetes. Of this group, 

 Amoebidium, Cienk., mav be regarded as the simplest form 

 (' Bot. Zeit.,' 1861, p. 169). 



The author announces his intention of describing the 

 whole group in a forthcoming work, which microscopists 

 will be glad to know is almost completed. — W. Archer. 

 3. Hemileia. — The Ceylon Coffee Fungus. — Owing to the 



