Overton—On the Boot Tips of Podophyllum Peltatum. 283 
come still more distinct. The vacuoles increase in size, number, 
and distinctness (figs. 6, 7). Gregoire (’06) describes the con¬ 
ditions at this period thus: 
“On voit le corps de chaque chromosome creuse de nombreuses cavites, 
petites et de formes tres variables, contenant un liquide non miscible a 
la substance chromosomique, non miscible non plus & l’enchyleme proto- 
plasmique et qui constitituera plus tard l’enchyleme nucleaire”. 
With this statement my observations, so far as they go, are in 
accord. By means of this alveolar-reticulate process the chro¬ 
matic granules, imbedded in the linin, as I have described above, 
become more widely separated. The formation of vacuoles and 
their inosculation produces a spongy structure with threads and 
plates in the linin substance, having denser and less dense por¬ 
tions, in which the chromatin remains suspended. This process 
continues until a truly reticulate condition arises with the chro¬ 
matin mainly at the junctures of the threads. In figure 7 an¬ 
astomosing vacuoles may be seen as well as unreticulated portions, 
which appear in the form of granules, platelets, and threads of 
different forms and sizes, so that the substance of each chromo¬ 
some, as Gregoire states, soon appears 
“en membranules, en lamelles, en filaments, de sorte que la vraie struc¬ 
ture de chaque chromosome est plutot celle d’une band spongieuse , \ 
but this process finally gives rise to the linin reticulum, in which 
are imbedded the chromatic granules. Beginning on the left of fig¬ 
ure 7, this process may be followed by successively observing the 
chromosomes to the right of this figure. The portion of the 
chromosome on the right is nearly entirely distributed. I do not 
find any marked tendency for the vacuoles at this stage to be ar¬ 
ranged along the chromosome axis, as claimed by Gregoire and 
others, although this condition may sometimes occur as shown in 
figure 6. I do not find a central undistributed axis, as seen by 
Haecker (’04) in Siredon. The vacuoles are distributed irregu¬ 
larly as a rule, and the entire chromosome finally becomes reticu¬ 
late. 
Gregoire (’06) states that the alveolation of the chromosomes is 
most distinct during the telophases, which is true of Podophyllum, 
but I think that in Podophyllum the process begins much earlier, 
even during the metaphases. The compactness of the chromo¬ 
somes often causes the stain to cover up entirely any traces of 
