STRUCTURE OF CERTAIN CHROMOSOMES 5 
chromosomes honeycombed by easily perceptible alveoles, 
of the existence of which there can be no doubt. For a detailed 
description of the characters of these alveoles, the reader will 
do well to refer to the paper quoted. Fig. 2, which is a slightly 
corrected copy of fig. 13"° of the same paper, shows the solid 
spiral threads into which these alveolated chromosomes become 
transformed during the telophase. 
Later, I have extended this study to the chromosomes of the 
nuclei of the pollen cells and of some tissues of Lilium 
croceum and L. martagon, and obtaimed exactly the 
same results. Combining these results with those of Grégoire 
and Wygaerts for Trillium grandiflorum and IT. 
cernuum,of Grégoire for Allium cepa, A. asca- 
lonicum, and A. porrum, and of Sharp (‘La Cellule’, 
xxix, 1913, p. 297) for Vicia faba, and rejecting as erroneous 
the statements of those writers who have described in plant 
chromosomes a spiral fibre instead of alveoles,! we find that all 
the plant chromosomes that have been successfully studied 
hitherto possess an alveolated structure in the prophases, 
equatorial phases, and anaphases. 
The present paper deals with certaim anim al chromosomes. 
Only one recent writer, Kowalski. has described any of these 
as alveolated. Kowalski (‘La Cellule’, xxi, 1904, p. 349), 
studying divers nuclei of the larval Salamander, arrived at the 
conclusion that their chromosomes all conform to the alveolation 
theory. I have carefully examined all the chromosomes studied 
by Kowalski, and many other of the Salamander larva, 
somes ; and that if this spiral cannot be made out with certainty (I think 
I sometimes catch glimpses of it), it is because the image of it is obscured 
by that of the walls of the alveoles. But this, if it exists, is certainly not 
the spirally coiled thread described by Bonnevie. I intend to return to this 
point in another paper. 
1 Bara necki’s observations may safely be rejected, because they have 
been controlled by Carnoy and by Stras burger, who didnot find the 
alleged fibre ; and those of Bonnevie on Allium, because they are con- 
tradicted by the everyday experience of botanical cytologists. Both these 
writers have apparently misinterpreted images of walls of alveoles, or of 
torsions of the whole chromosome, as images of a spiral fibre. 
