692 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Hansgirg also in ChrootJiece BicMeriana Hansg., Chroococcus turgidus 

 Nag., and Urococcus insignis Ktz. (Chroococcus macrococcus Ebh,). 

 True cliromatoph.ores are not to be found in the filiform conditions 

 of species of Lynghya or Oscillaria growing in air or water. 



The paper concludes with the description of a new species of 

 Oscillaria, 0. leptotrii-lioides, found on the walls of hothouses in 

 Prague, associated with Lynghya calcicola. 



Formation of the Spores of Cladothrix.* — M. A. Billet has 

 observed the formation of spores of Cladothrix dichotoma In water in 

 which human bones had been macerated. They are formed in the 

 interior of filaments with false ramification, not differing in appearance 

 from the vegetative filaments. When a spore is about to be formed, 

 the protoplasm of the filament, hitherto homogeneous throughout, 

 contracts into a rounded corpuscle of greater refrangibility, resembling 

 a cell-nucleus. This body elongates, contracts in the middle into 

 an hour-glass shape, and then divides transversely into ten cells of 

 rectangular form, each having a nucleus. These rectangular cells 

 round themselves off, and become elliptical sporiferous cells of which 

 the nucleus is the spore with a diameter of 1-1 • 5 fi. The spores are 

 united together into a zoogioea-like mass, and, on germinating, put 

 out a filament of smaller diameter than that of the spore, which 

 elongates into a new filament. 



The reagent used was dilute sulphuric acid (1 part acid to 3 of 

 distilled water) ; a dilute aqueous solution of methyl-blue and hsema- 

 toxylin being the best staining reagents. 



Aulosira.f — MM. E. Bornet and C. Flahault describe this genus 

 as forming a remarkable exception to the group of Algfe (or chloro- 

 phyllaceous Protophyta) to which it belongs, viz. the Nostocaceae. 

 While in the other genera, AnahcBna, Nodularia, Cylindrospermum, 

 Siphcerozyga, and Nostoc, tlje trichomes are naked, or if inclosed in a 

 sheath the latter is soft, gelatinous, and diffluent, the sheath of 

 Aulosira is thin, membranous, and dry. The relative position of the 

 spores and heterocysts is not sufficiently constant to be used as a 

 diagnosis of the genera. A new species, A. implexa, from Montevideo, 

 is described and figured. 



Microcystis.:]: — Dr. P. Eichter gives reasons for suppressing this 

 genus of Kiitzing, and for regarding it as a resting condition of 

 Euglena, which he agrees with Klebs in placing under Algae (or 

 chlorophyllaceous Protophyta) rather than under Infusoria. Of the 

 four species described by Kiitzing, M. Noltii (red), olivacea (olive- 

 brown), and austriaca (yellow), may all be determined to be forms of 

 development of Euglena viridis, M. olivacea agreeing exactly with 

 Klebs's description of the encysted condition of E. viridis ^ olivacea. 

 M. minor the author was not able to identify specifically with & 

 corresponding Euglena. 



* Comptes Keiidus, c. (1885) pp. 1251-2. 



t Bull. Soc. Bot. France, xxxii. (1885) pp. 119-22 (1 pi ). 



X Hedwigia, xxiv. (1885) pp. 18-20. 



