BRIEFER ARTICLES 
ABNORMALITIES IN PROTHALLIA OF PTERIS LONGIFOLIA 
(WITH FOUR FIGURES) 
Some abnormal conditions in archegonia were noted in prothallia, 
probably of Pteris longifolia. The spores had been sown about the 
middle of October, on moist sphagnum in a low jar covered with a 
glass plate. The resulting prothallia, after three weeks, were partly 
used in class work. Those remaining after class use were put aside for 
further development, in the hope of getting material for histological 
preparations. No particular care was taken to keep conditions con- 
stant or normal. The moisture varied greatly at times, and the tem- 
perature was a very variable factor, since for some time the jar was 
kept on the sill of a none too tight east window. As a result of some 
extremely cold weather, it was removed to a less exposed position on a 
shelf, somewhat darker than that on the window sill. In January the 
material was killed and fixed in 0.6 per cent chromacetic acid, washed, 
dehydrated, and imbedded in paraffin. The sections were cut 5 p thick. 
Safranin and gentian violet were principally used in staining. 
The prothallia were unusually small, and in sections the sex organs 
appeared smaller than is usual in Pteris. In spite of many normal 
archegonia, 8 cases were found in about 35 prothallia where there were 
more than two neck canal cells. In 5 of these, there were Poagased 
and certainly four such nuclei, either arranged in a row, as in fig. 1, or 
grouped closely together near the mouth of the canal. In the aR 
cases, the condition of the nuclei was such that it could not be ascertained 
whether the number was three or four. The four-nucleate neck canal 
cell has been reported for Filicineae by Miss Twiss' in Lygodium cir- 
cinatum, where occasionally this condition occurs instead of the usual 
two neck canal nuclei. 
A second abnormality which occurred in these prothallia is shown 
in fig. 2. Here there are evident two eggs, two ventral canal cells, and 
the usual two neck canal nuclei. This condition has been reported for 
* Twiss, Epira Minor, The prothallia of Aneimia and Lygodium. Bor. Gaz. 
49:168-181. pls. 10, II. gto. 
Botanical Gazette, vol. 53] (436 
