380 
The Ohio Naturalist. 
[Vol. VI, No. 1, 
to the distinct crest developed along one side. In the oldest 
stages it was found necessary to remove the hard covering of the 
seed before cutting. Several stains were em])loved among 
which were anilin-safranin followed by genetian violet, Dela- 
held’s haematoxylin and Haidenhein’s iron-alum-haematoxylin. 
The latter well known .stain proved to be the most successful in 
the stages of the develo])ment of the megaspores and embryo- 
sac, while Delafield’s stain gave the best results with the 
microspores. 
The flower of Sanguinaria begins its development early in the 
summer and the ovules and stamens are considerablv advanced 
by the end of September. Material taken on Oct. bth showed the 
single, hyjiodermal, archesporial cell di.stinctly differentiated 
(Fig. 2). The ovules at this time were just beginning to curve 
but no traces of the integuments were discernable (Fig.l). At 
this time the microsporocytes were just separating (Fig. 19) and 
a few of the tapetal cells already had two nuclei. There are 
three intermediate layers between the epidermis and tapetum 
(F'ig. 19). Material taken on Nov. 9th showed but little change 
in the development of the ovules, except that they had elongated 
and the curving was much more marked. The integuments were 
just beginning to make their appearance but the archesporial 
cell was .still undivided. At this time the micros]iorocytes had 
undergone some division and some tetrads were observed. The 
tapetal cells contained two nuclei (Fig. 20). 
By Dec. 9th the archesporial cell had divided twice giving 
rise' to the megasporocyte with two parietal cells above (F'ig. 2). 
The curving of the ovule was much more marked than in the 
previous stage and the beginnings of both integuments could be 
readilv seen in central sections. The division of the micro- 
si:»orocytes must have proceeded rather rapidly for at this time 
the micros])ores were present with large resting nuclei and the 
ta]>etum was dissolving (F'ig. 21). In this stage the microspores 
pass the winter. 
No material was taken from December until the finst of 
March when it seemed that the weather conditions were favor- 
able for the continued growth of the plant. Sections of material 
fixed March 1st .showed that there had been but little activity 
during the winter months. One of the ]>arietal cells had again 
divided so as to form a row of three cells above the large mega- 
sporocvte (Fig. 4). In some instances transverse divi.sion had 
taken ])lace forming a considerable tissue (F'ig. 5). The integu- 
ments had increased quite a little in size and now reached more 
than half way around the developing ovule. The curving of the 
ovule was com])lete at this time. The microspores were in 
])ractically the same .stage in which they were found in Decem- 
lier. The nucleus was undivided but the vacuole in the center 
