226 BOTANICAL GAZETTE [ APRIL 
observations of the embryo agree so closely with those of Pro- 
fessor Campbell (4) that it did not seem worth while to publish 
any drawings. One difference may be noticed here and this 
part of the subject may be dismissed at once. Campbell says 
that but three archegonia are formed at first, and only in case 
none of these are fertilized do others appear. I have found new 
archegonia appearing even after three embryos had begun to 
develop, two of which had made considerable growth. It thus 
appears that sometimes new archegonia may arise even after 
fertilization. 
The species selected for study were J. echinospora and I. 
Engelmanni, the former of which was examined more carefully. 
The material was collected by Mr. Raynal Dodge, of Newbury- 
port, Mass. Part of it was fixed at once, and part after it had 
been cultivated for some time in the laboratory. The fixing 
reagents employed were 1 per cent. chrom-acetic acid, and 
Flemming’s weaker solution. After remaining twenty-four hours 
in one of these fluids it was washed twenty-four hours in water and 
transferred through graded alcohols and chloroform or xylol to 
paraffin. The sections were, cut 5, 10, or 15m in thickness and 
stained in the ordinary way on the slides. Delafield’s hama- 
toxylin and erythrosin, safranin and gentian violet, Heiden- 
hain’s iron-alum-hzmatoxylin, and cyanin and erythrosin were 
all used with good results except in the case of the megaspore 
mother cell. 
THE STEM. 
The technique which is best adapted to an investigation of 
the development of the sporangia is not very suitable for an 
examination of the histology of the stem. Accordingly I have 
not attempted to make an exhaustive study of the latter, or of 
the vascular bundles of the leaf. Still the arrangement of the 
stem tissues is so peculiar that a few remarks will not be out of 
place. There is probably little variation in this respect in the 
different species. J. echinospora and J. Engelmann agree very 
closely with /. /acustris as figured and described by Farmer (1), 
whose account is the latest and best dealing with the structure 
