Notes o 
405 
genus was established by Braun 1 in 1851. Later, Berthold 2 described 
a species under the same name as Braun’s ( Aphanochaeie repens) 
considering that there was not sufficient reliable evidence for a specific 
separation. He found that his plant differed from that of Braun in 
possessing zoospores, which were enclosed in pairs in a delicate 
membrane at the time of liberation, and provided with four instead of 
two cilia. The hairs also were not articulated, and were swollen 
distinctly at the base. Rabenhorst 3 had cast considerable doubt on 
Braun’s observations by the figures, which he gives of Aphanochaeie 
repens , Br., in which he figures zoospores with four cilia, at first 
enclosed in pairs in a membrane. As Rabenhorst 4 mentions only 
having seen the authentic dried specimens, it was difficult to under- 
stand how he came to figure zoospores, differing so markedly from 
those described by Braun. This matter has been partly cleared up 
by Klebahn 6 , who publishes a note found amongst Braun’s manu- 
scripts after his death ; this shows that Braun had once more 
observed the formation of zoospores, and had come to the conclusion 
that there were four instead of two cilia. Although he mentions the 
occurrence of the zoospores in pairs, he did not observe the membrane 
described by Berthold in his species. Undoubtedly, however, Raben- 
horst had seen this note of Braun’s, and had taken his figures from 
those appended to the note. All species of Aphanochaeie at present 
known possess zoospores with four cilia. 
Although, as we see, there was thus little reason for separating 
Berthold’s species from Braun’s, Hansgirg 6 established for the former 
a new genus Aphanochaeie , Berth, non A. Br., at the same time 
merging the Aphanochaeie of Braun into the genus Herposteiron of 
Nageli, the distinctions drawn between this latter genus and Aphano- 
chaete , Berth., being that the former had multicellular hairs, which 
were destitute of a sheath, whereas the latter had unicellular hairs 
provided with a delicate sheath at the base. In the genus Herposteiron , 
Nag. (= Aphanochaeie, Br. non Berth.) were placed three species: 
(1) repens (A. Br.) Wittr. (Aphan. repens, A. Br. non Berth.), (2) con- 
1 Betrachtungen liber die Erscheinung der Verjiingung in der Natur, 1849-1850, 
p. 196, foot-note. English Transl. by Henfrey, 1853, p. 184, foot-note. 
2 Untersuchungen liber die Verzweigung einiger Siisswasseralgen (Nov. Act. Ac. 
Leop. Carol. XL, 1878), pp. 214 and 215. 
3 Flora Europaea Algarum, III, p. 304. 
4 Loc. cit., p. 391. 5 Pringsheim’s Jahrbuch, vol. 25, 1893, p. 288. 
6 Flora, 1888, p. 216. 
