No. 463.] STUDIES ON PLANT CELL.— VI. 491 
duce the terms ** maiosis” and the * maiotic phase " to cover the 
whole series of nuclear changes included in the heterotypic and 
homotypic mitoses. The maiotic phase is regarded as similar 
in its essential details in both animals and plants but the fact of 
its appearance at different points in the life histories precludes 
any probability of relationship in such widely divergent lines. 
The events of synapsis and the consequent peculiarities of the 
heterotypic and homotypic mitoses are considered as intercalated 
between the series of typical mitoses in the life history. 
Farmer and Moore's conclusions for Lilium candidum may be 
briefly summarized as follows. A definite spirem with the 
chromatin distributed as granules appears in the young spore 
mother-cell before its separation from neighboring elements. A 
“first contraction figure" now appears and the spirem thread 
becomes densely coiled in the vicinity of the nucleolus, this con- 
dition persisting for some time. Then the coils of the spirem 
loosen and become distributed about the periphery of the nuclear 
cavity, from the point of contraction as a center. A longitudi- 
nal fission of the spirem thread then appears, the chromatin 
granules dividing so that they come to lie in two parallel rows 
on the edge of the split ribbon. The fission is irregular and 
open loops appear at places. The spirem then shortens and the 
split gradually closes up and becomes very difficult to recognize. 
Many of the convolutions of the thread are attached to the 
nuclear membrane while the remainder form a tangle in the 
interior around the nucleolus which is believed to give up much 
of its substance to the chromatic portion of the spirem. Farmer 
and Moore then fail to find the double thread and its union dur- 
ing synapsis to form a single ( fusion) spirem which is a funda- 
mental feature of Allen's account. 
There follows then a stage which has been the subject of 
much discussion. According to Farmer and Moore the spirem 
thread becomes pulled out into V- and U-shaped loops, shown 
with especial clearness where the bend of the loop is attached te 
the periphery of the nuclear membrane. The arms of the V's 
then come to lie parallel and so close together as to give the 
structure which is really the result 
appearance of a fission in a 
two free ends of what was a loop. 
of an approximation of the 
