1899} BRIEFER ARTICLES 213 
THE SEXUALITY OF THE TILOPTERIDACEZ:" 
Ectocarpus pusillus Griffiths or Acinetospora pusilla Bornet possesses 
two forms of reproductive organs, the unilocular and plurilocular spo- 
rangia, whose elements present conditions intermediate between zoo- 
spores and aplanospores. I have recently encountered a third form of 
reproductive organ, the monosporangium, identical with that of Hap/o- 
jera Vidovichit Bornet or Heterospora Vidovichii Kuckuck, and this 
last species ought henceforth to be placed in the genus Acinetospora. 
These monospores are uninucleate, like the so-called oospheres of 
Saphospora speciosa (said to be the sexual form of Haplospora globosa), 
sad are covered by a membrane derived from the interior of the 
shosporangium, as are likewise the 4-nucleate monospores of Hapdo- 
pera globosa. Since they possess a membrane before their dehiscence 
they cannot be fertilized. On account of the frothy structure of their 
protoplasm and the great variation in their dimensions, they resemble 
neither oospheres nor spores. They germinate readily in cultures and 
teelop litle plants that bear the same kind of reproductive organs. 
ia them as gemmae or propaguda, and the organ that contains 
ee P ‘eudosporangium. From what we know of the Cutleriacee 
bsporg sel It is possible that the plurilocular sporangia of Acine- 
Psi metale organs whose oospheres germinate partheno- 
The wee € am will undoubtedly be found some day. 
lor Tlopteris fonclusion as to the nature of the monospores is justified 
and Haplospora. We are no longer able to admit that 
form ora qeures and oospheres similarly situated, of like 
and identical ee ventions, with the same protoplasmic structure 
lly while : ods of germination, but that the toi germinate 
{ Satisfactor € oospheres develop parthenogenetically. It seems 
~— Propagula ang . to say that one or the other of the elements are 
"© germinate at the 4-nucleate propagula are those that have begun 
upon the mother plant. 
We shall say then th Pp 
tige the ealy 4 : n that according to the present state of our knowl- 
and a. representatives of the Tilopteridacee, Tilopteris, 
‘ttheridia of Tilo Pree themselves solely vegetatively. The 
, th rudimentar Pteris give rise to true antherozoids that really seem 
a y structures, but it is by no means certain that they 
Bora et Ota is a résumé by the author of the paper entitled “‘ Les Acineto- 
WD, Bradley M. Dae’ Tilopteridacées,” Jour. de Bot. 13: —. 1899. Translated 
