206 SUMMARY OF CURRENT RESEARCHES RKLATING TO 



the galls has been referred to Urophlydis, and the author of this paper 

 retains the name, though his researches have caused him to doubt the 

 classification and relationship of the fungus. Sporangia developed from 

 resting spores form zoospores — one large and many small are frequently 

 to be seen, and there is some evidence of fusion — presumably sexual 

 fusion — between the two forms. An amoeboid stage follows, and 

 Plasmodia are found in the galls of young seedlings of Alfalfa. Rest- 

 ing spores are formed in cavities within the tissues of the galls. 

 The cytoplasmic and nuclear contents of the resting spores in the 

 dormant condition correspond to those of the plasmodium in the stage 

 immediately preceding the formation of resting spores. The disease 

 has only recently appeared in the United States. It has been known 

 for some time in Europe, and may cause serious loss. A. L. S. 



Sexuality in Mucors. — A. F. Blakeslke {Science, 1920, 51, 

 375-b2 and 403-9). The author makes a survey of the differentiation 

 of sex based on the results of his researches on JMucors. He discusses 

 imperfect hybridization, zygospore germination, environmental factors, 

 mutations, etc. He hopes that the study of Mucors may be of some 

 service in helping to solve the fundamental problems of sex. A. L. S. 



Sexual Differentiation in the Bread Moulds. — A. F. Blakeslee 

 {Proc. Soc. Exp. Biol, and Medicine, 1919, 16, lol). Blakeslee describes 

 shortly the sexual organs of the Mucorales : certain sexually primitive 

 forms are hermaphroditic with equal gametes ; from these forms 

 differentiation has proceeded towards inequality in the gametes and a 

 difference in the plants themselves. The male and female races remain 

 constant, though variations may occur in their sexual vigour. A. L. S. 



Occurrence in Britain of the Ascig-erous Stage of a "Brown 

 Rot" Fungus.— H. Woemald {Ann. Bot, 1921, 35, 125-35, 2 pis.). 

 The fungus described by the author occurred on mummied plums, on 

 one such mummy as many as twelve sporophores were formed of the 

 usual ScUroiinia type ; these formed the apothecial stage of the grey 

 mould Monilia cinerea so frequently found on plums and cherries. 

 Culture experiments and inoculation experiments were carried out suc- 

 cessfully. A. L. S. 



Occurrence in Britain of the Conidial Stage of Sclerotinia 

 Mespili Schell. — H. Wormald {Ann. Applied Biology, 1920, 7, 173-7, 

 1 pi., 2 figs.). Trees of 3Iespilus germcmica were observed for years to 

 be suffering from a form of brown rot. The cause was determined as 

 the Monilia form of Sclerotinia Mespili ; the Sclerotinia stage has now been 

 found in this country. Leaves, flowers and fruit are attacked by the 

 fungus. A. L. S. 



Pectin Relations of Sclerotinia cinerea. — J. J. Willaman {Bot. 

 Gaz., 1920, 70, 221-9). In this paper the writer records his observa- 

 tions on the behaviour of the fungus towards various pectic substances ; 

 in fruit-juice cultures it coagulates soluble pectin to calcium pectate by 

 means of the enzyme pectase. When the fungus invades a fruit tissue 

 it follows the line of the middle lamella, dissolving it out by means of 



