94 G. F. PAPENFUSS 



and G. Feldmann, that the tetraspores of these plants are the prod- 

 ucts of mitosis of haploid nuclei instead of meiosis as they usually 

 are in red algae and elsewhere in the plant kingdom. 



It is well known that in a number of red algae tetrasporangia 

 and sexual organs at times occur on one and the same thallus 

 (Svedelius, 1914; Kniep, 1928; and Drew, 1944). This suggests 

 that in certain instances typical tetrasporangia (with die content 

 divided into a tetrad of spores) actually may be formed by haploid 

 plants. To the knowledge of the writer, however, no cyto- 

 logical study has been made to explain the anomalous situations 

 presented by such plants or by the Bonnemaisonia-Hymeno- 

 clonium and Asparagopsis-FalJ^enbergia alliances. The sporangia 

 occurring on the sexual plants of Nitophyllum punctatum 

 (Stackli.) Grev. form a single uninucleate spore (Svedelius, 

 1914); and it has been shown by Yamanouchi (1906) and by 

 Lewis (1909) that the sporangia which are formed on certain 

 sexual plants of Polysiphonia flexicaulis (Harv.) Collins and 

 Griffiihsia globulifera Harv., respectively, also do not become 

 divided into tetrads, although the behavior of the nucleus in diese 

 sporangia could not be determined precisely. 



Kylin (1945) repeated the work of J. and G. Feldmann with 

 respect to the development in culture of the carpospores of 

 Bonnemaisonia asparagoides (Woodw.) C. Ag., and has con- 

 firmed their observations that the carpospores produce filamen- 

 tous stages which resemble Hymenaclonium serpens Batt.; and 

 he was inclined to accept the view that the latter is merely a stage 

 in the life of die former. However, in Kylin's cultures, typical 

 Bonnemaisonia plantlets developed as outgrowths from the Hy- 

 menoclonium-Xikt filaments. The anlages of the Bonnemaisonia 

 plandets somewhat resembled tetrasporangia, which fact caused 

 Kylin to conclude that J. and G. Feldmann had mistaken these 

 structures for tetrasporangia. In a subsequent article J. and G. 

 Feldmann (1946) adhere to their original opinion that these struc- 

 tures are tetrasporangia, the four spores of which in Kylin's cul- 

 tures, according to their interpretation, germinated in situ to pro- 

 duce collectively a Bonnemaisonia plant. Evidently the problem 

 is in need of further study. 



