Il8 MYCOLOGY 



which escape into the water. Under ceTtain conditions a cyst appears 

 in place of a zoosporangium. This is thick-walled and of a yellow 

 color and enters a period of rest. After the rest period, the membrane 

 of the cyst rupture and a sporangium appears. Cysts may arise 

 by a kind of sexual union where two unlike mycelia fuse and the 

 protoplasm of both flows out to form a cyst between the original cells. 

 Urophlyctis pulposa attacks leaves and stems of Chenopodium and 

 A triplex species. U. alfalfcB grows in the roots of the alfalfa in 

 South America and Germany. 



Family 5. Ancyclistace^. — This is a small family consisting 

 of fungi whose mycelium is very slightly developed and not easily 

 distinguished from the fruit body. In one subfamily Lagenide.£, 

 the mycelium is entirely absent. In the ANCYCLiSTE.a;, there is a 

 rich development of the mycelium which forms lateral tube-like 

 branches, which penetrate other cells. The fruit bodies are sac-hke 

 and give rise to zoospores. Sexual organs are present as antheridia 

 and oogonia, the contents of the former passing over completely into 

 the latter. The oospore, which is formed, is found free in the oogonium. 

 All of the known members of this family are endophytic parasites and 

 the different stages of their development are short-lived. 



Lagenidium entophytum lives in the zygospores of species of Spiro- 

 gyra. L. Rabenhorstii parasitizes the cells of Spirogyra, Mesocarpus, 

 Mougeotia. L. pygmcRum lives in the pollen grains of diverse species 

 of Pinus. 



BIBLIOGRAPHY OF OOMYCETALES 



Atkinson, George F.: Damping Off. Bull. 94, Cornell University Agricultural 

 Experiment Station, May, 1895; Notes on the Occurrence of Rhodochytrium 

 spilanthidis Lagerheim in North America. Science, new ser., xxviii: 691-692, 

 Nov. 13, 1908; Some Fungus Parasites of AlgK. Botanical Gazette, xlviii: 

 321-338, November, 1894. 



Clinton, G. P.: Oospores of Potato Blight, Phytophthora injesians. Report Conn. 

 Agricultural Experiment Station. Part x. Biennial Report of 1909-1910: 

 753-774; Oospores of Potato Blight. Science, new ser., xxxiii: 744-747, 

 May 12, igii. 



Claussen, P.: Ueber Eientwicklung und Befructung bei Saprolegnia monoica. 

 Ber. d. Deut. Bot. Gesellsch., xxvi: 144, 1908. 



COKER, W. C; Another New Achlya. Botanical] Gazette, 50: 381-382, November, 

 1910. 



Davis, Bradley M.: Cylological Studies on Saprolegnia and Vaucheria. The 

 American Naturalist, xlii: 616-620. 



