ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 791 



from the receptacle ; it develops into a structure consisting of carpo- 

 gonic cell, trichophoric cell, and trichogyne. The latter is mostly 

 unicellular, though in some cases branched and septate. The carpo- 

 gonium becomes binucleate, though the process was not seen, and the 

 trichogyne degenerates. Stages of ascus and spore-formation are also 

 described, with the relation to the host, etc. 



Infection by Ergot Spores.* — R. Falck gives the results of his 

 studies on the subject of spore dispersal, especially in Glaviceps purpurea, 

 by the agency of air currents. Spore-ejaculation from the asci is aided 

 both by the form of the ascus and the uniform size of the spores. The 

 spores of Glaviceps are carried by the wind to the developing flower. 

 As the wind blows in a parallel plane to the earth, the spores are carried 

 along great distances at the same level. 



Mildew of Cherries.f — Fr. Muth states that owing to the cold 

 summer of 1910, the fungus Sphserotheca pannosa spread widely on 

 cherry trees. The mildew, which is also found on apples, is described, 

 and remedial measures are suggested, such as pruning back the twigs 

 attacked in the early part of the year, burning all fallen wood, and 

 spraying with Bordeaux mixture. Sprinkling with sulphur as soon as 

 the disease appears is also recommended. 



Sphaerotheca Castagnei Lev.f — 0. Winge has studied this fungus 

 about which there has been much controversy in regard to the occurrence 

 in it of fertilization. According to the results obtained by him, the 

 organs which are formed before the perithecium are sexual organs, which 

 are, however, entirely f unctionless. The antheridium has a great affinity 

 for the oogonium, and frequently the two organs are closely united, but 

 no fusion has ever been observed between them. He holds that the 

 male nucleus does not pass into the female cell, the latter developing 

 parthenogenetically. It is desirable to study further the behaviour of 

 the chromosomes. 



Experimental Researches with Uredineae.§ — E. Mayor records the 

 results of various experimental cultures with teleutospores taken from 

 several species of Garex and infected on Ribes alptnum, R Grossularise, 

 etc. He was not quite decided whether he was dealing with one or 

 several species of Puccinia, nor whether the Uredine was the same as 

 those described by Klebahn. Mayor also made experiments with the 

 ascidiospores of Puccinia longissima on Endophyllum Sedi, and with those 

 of Grepis biennis, which he proved to be associated with the teleutospores 

 of Garex muricata. He describes very carefully the different spores 

 of the life-cycle of Puccinia Actseae-agropyri, and the experiments under- 

 taken to test the different stages of growth. 



Jakob Eriksson || publishes a preliminary note on his investigations 



* Zeitschr. Forst.-Jagdw., 1911, pp. 202-27 (4 figs.). See also Bot. Oentralbl., 

 cxvii. (1911) pp. 195-6. 



t Zeitschr. Wein-Obst-Gartenbau, vii. (1910) pp. 165-9 (3 figs.). See also Bot. 

 Oentralbl., cxvii. (1911) p. 224. 



t Bull. Soc. Mycol. France, xxvii. (1911) pp. 211-19 (2 pis.). 



§ Ann.Mvcol., ix. (1911) pp. 311-62 (tigs.). 



U Centralbl. Bakt., xxxi. (1911) pp. 93 5. 



