QUA.RTERLY CHRONICLE OF MICROSCOPICAL 

 SCIENCE. 



BOTANY. 



1. Algse. — 1. Spores of Nostochacece. — In a paper ('Ann. des 

 Sc. Nat./ 5e ser., xix, p. 119) on the reproduction of some 

 species of this group 'belonging to the genera Spermosira 

 and Nostoc, Janczewski announces the discovery of spores in 

 the latter genus, an observation already anticipated by Archer 

 in Nostoc paludosum, one of the species in which it has now 

 again been detected (' Quart. Journ. Micr. Sc./ 1872, p. 367). 

 In a subsequent number of the volume, Bornet (p. 318) 

 confirms this discovery in numerous other species. He had 

 ■already in his memoir published, in the seventeenth volume, 

 announced the reproduction by spores of Glceocapsa. 



2. Conjugation of Zoospores in Confervacea. — Areschoug 

 has recorded the interesting fact ('Act. Reg. Soc. Sc. Ups.,' 

 ser. iii, vol. ix) of the conjugation of the zoospores of various 

 Confervacefe ; amongst others, of two very widely diffused 

 species — Cladophora sericea and Enteromorpha compressa. 



3. Morphological Differentiation of the Sphacelaria-series. 

 — i. Pringsheim points out {' Abhl. der k. Akad. d. Wiss. zu 

 Berlin,' 1873) that some Thallophytes oflFer distinct transi- 

 tions to a cormophytic mode of bud-formation. These increase 

 in interest when they occur as terminal links of a series, for it 

 appears natural to assume that such a series corresponds to 

 the genetic progress of development of the forms, and indicates 

 the various paths which have led on to cormophytic bud- 

 formation. In the different subdivisions of the Algae, several 

 progressive and parallel series lead from the simple con- 

 fervoid type of growth up to bud-structure. Amongst the 

 Floridea the C^rammm- series affords an example. 



A far more perfectly developed and almost rectilineal series 

 is presented by the Sphacelaria-series, belonging to Phaos- 

 poreae. It compreheuds the Ectocarpeee, the Sphacelariea 

 proper, and some smaller genera. The final link of this series, 

 Cladostephus, shows a great approximation in its mode of 

 growth to cormophytes. The Ectocarpeee, which form the 

 lowest links of the series, are plants of purely confervoid 



