74 COMPARATIVE EMBRYOLOGY. OF THE RUBIACEAE 
phase of the first and second pollen division and in the first, second, 
third and fourth embryo-sac divisions, is in Crucianella the hitherto 
unobserved and surprising number ten, in Asperula, twelve. 
These numbers, however, are believed, on the basis of a large 
number of counts at different times, to be inconstant. In Crucia- 
nella eight to eleven have been counted, and in Asperula a similar 
amount of variation has been observed. Allowing for error in 
counting, which, in these plants is not great, both on account of 
the smallness of the cells (with the consequent frequency with 
which the whole nucleus appears in a single thick section) and of 
the number of chromosomes, I believe it must be maintained that 
variation in this regard occurs, and that this is a fact which has 
heretofore received insufficient recognition. 
The condensation of the chromosome pairs proceeds all through 
the prophase until the equatorial plate has been completed, when 
they take the form of a double Vs, one of which lies above and 
one below the equatorial plane, with theis ‘angles directed toward 
the axis of the spindle. This arrangement is difficult to recognize 
in metaphase on account of the extreme condensation of the chro- 
mosome, but in very early anaphase may be seen with sufficient 
distinctness. 
My observations and conclusions appear to coincide with those 
of Duggar* for Peltandra. That author's interpretation of his 
figures of the corresponding division in Symplocarpus as indicating 
a qualitative division, however, would in my judgment seem not to 
be justified. For the chromosomes are here, as represented in 
Pl. 1, figs. 7 and 7a of Duggar's paper, of double V-form with the 
angle directed toward the center of the spindle. These separate 
first at the angle, and the degree of similarity in the two plants is 
So great as to render them susceptible of but a single interpreta- 
tion, which is opposed to the view that there is a qualitative divi- 
Sion, unless it can clearly be shown that the separation of the limbs 
of the V is a separation, not at their ends, but across the middle 
of the chromosomes. 
Attention should further be directed to the above mentioned 
observation, namely, that in diakinesis and the later prophase the 
Mene ERR nd a 
* Studies in the development of the poll in ; d 
Peltandra undulata. Bot. Gaz. 19: 81. Fr grain in Symplocarpus foetidus an 
