June, 1922] FARR — • MEIOTIC CYTOKINESIS OF NELUMBO 
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both ends. It might be well at this place to explain the term "interkine- 
sis," which I employed in my recent paper on Sisyrinchium (8) and am 
using again in the present paper. In 1912 Lundegardh (14) introduced the 
term ''interphase" to refer to the interval between two successive mitoses. 
He used it, however, in all cases to refer to the condition of the nucleus dur- 
ing that interval, making it coordinate with "prophase," "metaphase," 
etc. Sharp (16) in 19 14 called attention to this meaning of the term, so 
that it now seems well established in cytological literature. It now appears 
that we need a term to refer to the condition of the entire cell between the 
time of the completion of cytokinesis and the initiation of the next succeed- 
ing karyokinesis. It is evident that the interphase condition of the nucleus 
may begin during cytokinesis, so that a new term coordinate with karyo- 
kinesis and cytokinesis is required, and "interkinesis " seems to be the logi- 
cal choice. Throughout the study of Nelumho lutea it was found that the 
karyokinetic stages in the reduction divisions seemed to be relatively few, 
whereas the cytokinetic and interkinetic stages were quite prevalent. 
This leads to the conclusion that karyokinesis proceeds in this form much 
more rapidly than cytokinesis, which hardly agrees with the findings of 
Lubimenko and Maige (13) in other species of this family. 
The metaphase of the heterotypic division presents a very long spindle 
with a very narrow equatorial plate of chromosomes. The spindle is usu- 
ally quite straight, though cases were noted where it curves gently at the 
poles. As nearly as could be determined the number of chromosomes is 
eight, though in some cases apparently good polar views revealed not more 
than five or six. This would of course be the gametophytic number. Ap- 
parently the number of chromosomes has never before been counted in this 
species. In 1898 Guignard reported 32 chromosomes in Nymphaea alba, 
and the following year Strasburger reported 48 for the same species. In 
1897 Guignard reported 16 as the diploid number in Nuphar liUeum, while 
Lubimenko and Maige in 1907 and Rosenberg in 1909 agree that the hap- 
loid number is 17. 
The halves of the dyad chromosomes pull apart in the anaphases and 
pass to the poles in the usual manner. In the telophases the distance 
between the two plates of chromosomes is usually equal to or greater 
than the distance from either of these to the plasma membrane at 
its nearest point. Very soon after the chromosomes take this position the 
spindle fibers become apparently thicker along their middle portions. 
Whether this is due to a real thickening of the fibers themselves, or whether 
it is more or less of an illusion brought about by the crossing of fibers which 
lie nearly parallel to each other, is difficult to determine. But it soon be- 
comes evident that a real thickening of the individual fibers has occurred, 
as there is formed a cell plate of these thickenings. These thickenings, 
which at first appear spaced, thicken until they touch each other, making a 
continuous layer. It does not extend beyond the limits of the central 
