378 SUMMARY OF CURRENT RESEARCHES RELATING TO 



As regards the systematic position of the fungus, Leitgeb con- 

 siders that it may bear a similar relation to the Peronosporese to 

 that of the Chytridiaceae to the Saprolegnieee ; in both we have 

 degraded forms in which the production of sexual organs has been 

 lost, the resting spores taking their place. 



Rehm's Ascomycetes. — This most valuable and important collec- 

 tion of dried ascomycetous fungi has now reached twelve parts, and 

 includes no fewer than 600 species, 281 belonging to the Discomy- 

 cetes, and 319 to the Pyrenomycetes. Of these 59 of the former and 

 37 of the latter are new. The most recently published part contains 

 detailed and exact descriptions of all these new species, as well as 

 critical remarks on all the other species already included in the 

 collection. 



Destruction of Insects by Yeast. — In 1880 we called attention* 

 to some experiments of Professor H. A. Hagen, of Cambridge, Mass., 

 the results of which showed (he considered) that the yeast fungus 

 entered the body of the insect on which it was sprinkled, and pro- 

 duced a gi'owth fatal to the life of the insect. Professor Lankester, 

 however, at the time pointed out that the more probable explanation 

 was that the yeast fungus itself was innocuous, but that it was a vehicle 

 for such a parasite as " green muscardine " {Isaria destructor), which 

 Metschnikoff found was best cultivated by the use of beer-mash. 



Mr. T. H. Hart, of Ashford, having tried the application of yeast, 

 reports f to Professor Hagen that while a first experiment was 

 successful all subsequent ones failed, and he feared therefore that 

 yeast is too uncertain in its application to be of practical use. To 

 this Professor Hagen replies as follows : — 



" It seems evident that the yeast has not contained Isaria or 

 other fungi obnoxious to insects to which the first success could be 

 ascribed ; otherwise the later application of the same fluid ought to 

 have had the same effect, or even by the multiplication of the fungi 

 a more marked effect. 



" Experiments made in Germany and here (U.S.A.) had exactly 

 the same result — first success, later failure. . . . After all, I 

 believe it can be concluded that a certain stage of the yeast solution 

 is needed to make it effective, and that after this stage it becomes in- 

 different. That yeast solution has killed insects seems to be un- 

 doubtedly proved, and it remains only to find out the stage in which 

 its application is successful. It is sure that success, even in a very 

 small number of experiments, cannot be annihilated by failure in 

 other experiments." 



Development of Fungi on the Outside and Inside of Hens' 

 Eggs.J — C. Dareste put an egg (for artificial incubation) in a 

 vessel hermetically closed by an indiarubber stopper, and of small 

 capacity (about 0*35 litre). On the sixth day the egg was covered 

 with green spots of fructified mould ; then there appeared on the 



♦ See this Journal, iii. (1880) pp. 246-8. 



t Canadian Entomologist, xiv. (1882) pp. 38-9. 



X Comptes Rendus, xciv. (1882), pp. 4G-9. 



