784 SUMMARY OF CURRENT RESEARCHES RELATING TO 



In reference to Bcnt'ujcra, wLich has been cstablislicd as a section of 

 Cliytridinm by M. Felix Kosen,* if all the si)ccies whose sporangia possess 

 a basilar swelling are placed in the genus Jihizidium, the section Dcnii- 

 gera ought not to remain in the genus Chijtridium, but become a jjart of 

 the genus lihizidium. 



When the author in his former paper gave a description of the genus 

 S2)1i8crita, he was unable to follow the development of the cysts for want 

 of proper material. Since then the cultures have beeu continued, and 

 a niimber of cysts obtained ; their development resembles that of the 

 sporangia, but from the first the protojilasm is denser, and there are no 

 sexual phenomena apparent. Their form is sometimes spherical ; moro 

 often they are elongated and elliptical. 



The author then describes a new Pyrenomycete which attacks Sali- 

 cornia licrhacca, under the name of Pleospora Salicorniae. 



Protoph.yta. 



Relationship between Phormidium and Lyngbya.f — M. M. Gomont 

 has been able to follow the course of develoi>ment of an Oscillaria, the 

 study of which was interesting as bearing on the relationship between 

 the genera Phormidium and Lyngbya. The plant (^Oscillaria viridis), 

 which presented all the characters of a Phormidium, was cultivated in two 

 ways — in a vase filled with water, and on a brick which was simply kept 

 moist. The trichomes in both cases became strongly flexuous, and were 

 surrounded by solid sheaths. These sheaths had, however, no tendency 

 to agglomerate, and the filaments could be separated without tearing by 

 the aid of needles. In fact, it ai)peared as a true Lyngbya. It remains 

 then proved that the same plant can possess the characters of Phormidium 

 as well as those attributed to Lyngbya. 



Cultures of Cladothrix dichotoma.| — M. E. Mace states that Clado- 

 ihri.v dichoioma Cohn is a filamentous bacterium found in fresh or 

 salt, but especially abundant in stagnant water. In the cultures made 

 with gelatin, the colonies appear on the foiu'th or fifth day as very small 

 yellowish points surrounded by a brown ring. All the cultures emitted 

 a somewhat mouldy odour. On the filaments of the cultures true ramifi- 

 cation could be observed ; on the side of the filament a rujiture appeared 

 which was indicative of a lateral branch. This bud enlarged and formed 

 a cylindrical prolongation until it attained to the same size as the mother 

 filament. On the same filament, frequently a series of these lateral 

 branches at difierent stages of development could be observed, and it was 

 thus possible to follow the transformations. The author concludes by 

 stating that Cladothri.v dichotoma appears to be a saprojihytic bacterium 

 inofiensive to men and animals. It very probably may take a large part 

 in the calcareous concretions which are found deposited in the pijies 

 used to conduct certain waters. The bacterium brings about the precipi- 

 tation of lime salts around its very long filaments, in the same manner as 

 Leptothrix huccalis occasions the precij)itation of the lime salts in saliva. 



New Pleurocapsa.§ — Herr G. Lagerheim describes a new species of 

 this genus, hitherto exclusively marine, P. fiuviatilis, growing attached to 

 mosses on wet planks in the canal of the Dreisam near Freiburg-i.-Br. 



* See this Journal, 1888, p. 1002. 



+ Soc. Bot. et Glycol, de France, Session Cryptogamique, 1887 (1888) pp. 18-21. 



X Comptes Eeudus, cvi. (1SS8) pp. 1622-3. 



§ Notarisia, ill. (1888) pp. 429-31 (1 fig.) 



