208 Nichols, A morphological study of Juniperus communis var. depressa. 
before the initiation of metakinesis becoTncs distinctly bipolar 
(fig. 26). The chromosomes, which after the disappearance of the 
nuclear membrane have become crowded together, are rapidly 
oriented toward the nuclear plane and assume a position approxi- 
mately perpendicular to the axis of the spindle. In this position 
it is possible, in sections cut perpendicular to the spindle axis, to 
connt twelve chromosomes, which represent the reduced number 
characteristic of the gametophyte (fig. 27). In the megaspore mother 
cell of the European J. communis Noren (1907) finds only eleven 
chromosomes. It is not surprising, however, that there should be a 
divergence of opinion on this point, since not only are the objects 
under consideration very minute, but even in sections which are 
favorably cut and stained the chromosomes are crowded and usually 
appear to overlie and merge into one another, so that their accurate 
enumeration is extremely difficult, nor is it impossible that the 
number in var. depressa differs from that in the European form. 
In view of Noren’s results a careful recount was made, but 
although cases are frequent where only eleven can be seen, in 
some instances at any rate it was determined with considerable 
certainty that there are twelve chromosomes. 
The chromosomes are short and thick, but as they lie in the 
equatorial plane the various L,Y, X, Y, and 0 forms characteristic 
of the heterotypic division are often recognizable. The spindle 
fibers are attached at or near the inner ends of the danghter chro¬ 
mosomes, and their Separation begins at this point. Düring the 
anaphase the daughter chromosomes are drawn apart and as they 
approach the poles it can be seen that they have undergone a 
second longitudinal fission (fig. 28). Just what significance should 
be attached to this fact is doubtful, but in the light of subsequent 
events it seems hardly possible that the Segments formed at this 
time are homologous with those of the homotypic division, as is 
maintained by Strasburger (1900). At the poles the chromosomes 
come together and form a seemingly homogeneous, lumpy mass in 
which no structure can be made out (fig. 29). 
The reconstruction of the daughter nuclei is apparently brought 
about without the formation of a definite spirem, in a manner 
similar to that described by Lawson (1903) and elaborated by 
Gregoire and Wygaerts (1904). Lacunae appear within the 
mass of chromosomes, increase in size, flow together, and force 
the surrounding chromatin outward (fig. 30). Alveoli then divide 
the chromatin into smaller masses, until there is formed eventually 
a well developed resting nucleus in which the identity of the indi¬ 
vidual chromosomes is completely lost (fig. 31). Miss Ferguson 
(1904) finds that in Pinus the chromosomes unite end to end and 
form a definite spirem which in turn gives rise to the reticulum 
of the daughter nuclei. There is no stage, however, in the Or¬ 
ganization of the daughter nuclei in J. communis where a continuous 
spirem can be recognized. The nuclei are spheroidal, somewhat 
broader than long and slightly flattened on the equatorial surface. 
