472 BOTANICAL GAZETTE [june 



Farmer and Digby (13) published some very interesting results 

 of their cytological studies of apospory and apogamy in ferns. 

 Five of the 7 species which they investigated produced game- 

 tophytes aposporously. The aposporous nature of the 4 following 

 was observed first by Druery: Athyrium Filix-Joemina var. 

 clarissima Jones, A. Filix-foemina var. clarissima Bolton, Scolo- 

 pendrium vulgare var. crispum Drummondae, and Lastrea pseudo- 

 mas var. cristata apospora. The fifth, Athyrium Filix-foetnina var. 

 uncoglomeratum, was first observed as an aposporous form by 

 Stansfield (20). The origin of the aposporously produced 

 prothalKa in the different ferns was studied with special reference 

 to changes in the chromosome number, and it was discovered that 

 either the haploid or the diploid number is retained throughout the 

 Ufe cycle. In Athyrium Filix-foemina var. clarissima Jones, the 

 embryo formed by the prothaUia of aposporous origin is apogamic. 

 Ninety chromosomes, the diploid number, are found in both genera- 

 tions. The embryo of Lastrea pseudo-mas var. cristata apospora is 

 also of apogamic origin, but the chromosome number, between 60 

 and 78, is probably the reduced number. The other 3 species were 

 found to be parthenogenetic. In Athyrium Filix-foemina var. 

 clarissima Bolton, 84 chromosomes were counted, in A . Filix-foemina 

 var. uncoglomeratum about 100, and in Scolopendrium vulgare var. 

 crispum Drummondae 70 chromosomes were found in the game- 

 tophyte, and between 80 and 100 in the embryo sporophyte. Since 

 64 chromosomes were present in the sporophyte of this species, 

 Farmer and Digby were inclined to beheve that the diploid number 

 of chromosomes are present. 



WoRONiN (12, 24) studied apogamy and apospory in the follow- 

 ing species of ferns: Trichomanes Kraussii, Pellaeaflavens, P. nivea, 

 P. tenera, Notholaena Eckloniana, and N. sinuata. In Trichomanes 

 Kraussii sporangia were not produced, but prothallia were formed 

 in large numbers from portions of leaves which were brought into 

 contact with the soil. According to Woronin, antheridia were in 

 some instances produced directly from the leaves of the sporophyte. 

 It appears, however, that there is not an omission of all the pro- 

 thalHal portion, but that there is formed in each case a short filament 

 which may not be considered as the stalk of an antheridium. 



