122 Morphologie und Teratologie. — Physiologie. 



own and other authors observations on the floral development, 

 leaves the question open. W. H. Lang. 



Campbell, D. H., Studies on the Gametophyte of Sela- 

 ginella. (Annais of Botany. Vol. XVI. 1902. p. 419.) 



This is a reinvestigation of the early stages of development 

 of the gametophyte of Selaginella Kraussiana. The account 

 of the development of the spore-membranes and the character 

 of the protoplast given by Fitting was confirmed, and, except 

 as regards the young protoplast, the author's previous descrip- 

 tion was found correct. The nuclei are at first uniformly distri- 

 buted through the cytoplasm of the young spore. Later a 

 definite cellular body, three cells thick in its central part, is 

 formed at the apex of the spore; it is separated by the thicke- 

 ning of the inner walls of the lower layer of cells from the 

 undivided spore-cavity below. At the time the spores are 

 shed the central vacuole is miich reduced in size though still 

 evident. W. H. Lang. 



Thistleton-Dyer, Sir W. T., Mor phological Notes. VIII. 

 On Polycotyledony. (Annais of Botany. Vol. XVI. 1 902. 

 p. 553.) 



Seedlings of Acer Pseudo-platanus with three cotyledons 

 were observed in considerable numbers at Kew. They ressem- 

 bled those discussed by Duchartre, who explained such forms 

 as due to the more or less complete bi-partition of one cotyle- 

 don rudiment. This explanation did not suffice for the speci- 

 mens described in this paper. In some of these three cotyledons 

 were succeeded by three foliage leaves and the arrangement of 

 the latter in plants grown on in pots was ternary during the first 

 and second years; they reverted however to the ordinary type with 

 opposite leaves in the third year. The author suggests that in 

 all these cases the embryo is provided with three instead of 

 two cotyledons, two of which may subsequently coalesce into 

 one, the resulting structure being more or less deeply bifid. 

 The same explanation would apply to the similarly arranged 

 epicotylar leaves. In the latter portion of this paper the points 

 of view, from which the cotyledons should be regarded are 

 briefly discussed. W. H. Lang. 



BoiJILHAC, RaOUL, Influence de l'aldehyde formique sur 

 Ia Vegetation de quelques algues d'eau douce. 

 (Comptes rendus de l'Academie des Sciences de Paris. 

 29 Decembre 1902.) 



L'aldehyde formique peut servir d'aliment au Nostoc et ä 



YAnabaena, cultives dans une Solution nutritive assez peu 



eclairee pour que ces plantes soient obligees de vivre aux 

 depens d'une matiere organique. 



