THE SPERMATOGENESIS OF Hysprip PEas 533 
have spores which might be of pure descent or might not be so 
according to the manner of the orientation of the segments in the 
metaphase of the first division. The chromosomes might be as- 
sociated and distributed by chance as I have recognized (Cannon, 1) 
and as Sutton has dwelt on at length.* What the connection of 
the chance distribution of the chromosomes may be with the 
distribution of the characters among the hybrids is not at all 
clear, since the relation of the chromosomes to the characters 
is not known, but the cytologist has abiding faith that there 
is some connection which will be demonstrable with the micro- 
scope, and he looks to the field of hybrids and of hybridization as 
a new opportunity for experimentation by which to supplement 
and to substantiate the results of his studies. Experimentation 
and cytological studies on hybrid forms in which the number of 
chromosomes is known and in which the number of characters 
has been determined should show a connection, if there is one, 
between the number of characters that are transmissible and the 
number of the chromosomes and their morphology. I wish here 
to call attention to what very likely is merely a chance coinci- 
dence, but nevertheless suggestive and interesting, namely, to the 
agreement in the number of the groups of constant differentiating 
characters as given by Mendel for the peas used by him in ex- 
periments with the reduced number of chromosomes in the peas. 
As given by Bateson (Bateson, 1), the characters are (a) differences 
in the length and color of the stem ; (4) in the size and form of the 
leaves ; (c) in the position, color and size of the flowers; (¢) in 
the length of the flower-stalk ; (¢) in the color, form and size of 
the pods ; (/) in the form and size of the seeds ; (g) in the color 
of the seed-coats and cotyledons. In the peas there are evidently 
more appreciable characters than chromosomes, and therefore the 
chromosomes bear more than one character each. If then the 
chromosomes maintain their individuality certain characters might 
be associated together in the same chromosome, and might be 
borne in mind, however, that a difficulty in drawing conclusions at present from the 
results of Rosenberg’s studies of the sporogeny of the Drosera hybrid may lie in the 
partial sterility of the form. (See Focke, Pflanzenmischlinge, I 55.) Further work 
on this hybrid is promised and will be awaited with interest. 
* Sutton, W. S. The chromosomes in heredity. Biol. Bull. 4: 231. 1903. 
