ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 397 



become transformed into asei, and the two nuclei fuse. The most 

 careful search revealed no other fusion, nor any pairing of nuclei. 



The behaviour of the ascus fusion nucleus was also studied ; the first 

 mitosis was heterotypic, the second homotypic, and the third typical. 

 Chromatic reduction takes place according to the hetero-homotypic 

 scheme in the two first divisions ; the third division is vegetative. 



In Peltigera there is a special peculiarity in that the nucleolus and 

 nuclear membrane disappear at an early stage. Also in other Ascomycct - s, 

 while the haploid number of chromosomes is generally four or eight, 

 they are reduced in the lichen to two. Thus two chromosomes with 

 two branches appear in the prophase of the first mitosis of the ascus ; 

 the second mitosis shows two chromosomes which had already divided 

 longitudinally towards the end of the preceding division ; in the third 

 mitosis the tw<o chromosomes are simple, and remain so in all succeeding 

 divisions, both of vegetative and ascogonial hypha?. 



The writers conclude that in these lichens there is no fusion of 

 nuclei in the ascogonium ; the only karyogamy is that in the ascus, and 

 is immediately followed by a chromatin reduction, which presents the 

 same characters as in other living organisms. 



■- 



Mycetozoa. 



(By A. Lorrain Smith, F.L.S.). 



Japanese Mycetozoa.* — Gulielina Lister has received during the 

 last eight years a series of letters and specimens from Kamagusu 

 Minakata, and now records the results of her work on these. Until 

 Minakata began his investigations very little was known of Japanese 

 Mycetozoa ; now, thanks to his researches, there are 110 species recorded, 

 three of which are new to science, and much new information has been 

 gleaned as to distribution, variation of species, etc. G. Lister gathers 

 from a comparative study of species found in Britain, in tropical Ceylon 

 and in Japan that the latter country stands midway between the other 

 two in regard to species, though more investigation is needed to decide 

 the Ojuestion accurately. A descriptive list of Japanese species is given 

 along with quaint notes by Minakata. 



Schizophyta. 

 Schizomycetes. 



Protozoa in Relation to the Factor Limiting Bacteria? Activity 

 in Soil.t — T. Goodey, as the result of experiments conducted with 

 samples of old soils from Broadbalk and Barnfield bottled in 1846 and 

 1^70 respectively, has come to the conclusion that protozoa, including 

 ciliates, amcebas and flagellates, added to soil are not able to act as a 

 factor limiting bacteria 1 activity in soil, and that inferentially such 

 organisms obtainable from ordinary soil under cultural conditions do 



* Trans. Brit. Mycol. Soc, v. (1915) pp. 67-84 (1 pi.). 

 t Proc. Roy. Soc, Series B, lxxxviii. (19151 pp. 437-56. 



