OcroBer 18, 1918] 
mitochondrium. The mitochondria at no time 
contained any orange-colored droplets or any 
droplets at all. Neither did they become 
rounded, loop- or ring-shaped. As a matter of 
fact, they behaved in a manner quite like what 
has been described as normal for the cells of 
tissue cultures (Lewis and Lewis, 1915).8 
Once a loop-shaped mitochondrium was seen, 
but this unbent and became a thread again 
without the formation of any globule. The 
very small orange-colored droplets unite into 
larger ones, others appear in the cell, and thus 
in the course of five or six hours several addi- 
tional fat droplets of different sizes can be 
seen. While this process is going on, the fat 
droplets previously noted and drawn take on a 
bright orange stain, so that in a very short 
time it is impossible to distinguish by means 
of color those droplets which were present in 
the cell before the addition of the Sudan III. 
yolk. The color exhibited by the fat droplet 
in the living cell, while a bright yellowish-red, 
was never the same shade as that obtained in 
a culture fixed and stained with Sudan III. 
Nile blue sulphate could not be used in these 
experiments because as has been previously 
shown, it stains bodies that are not fat in the 
living cell. The fat droplets of the mesen- 
ehyme cells remain distinctly smaller than 
those of the clasmatocyte. Neither the 
mesenchyme cell nor the clasmatocyte were 
ever observed in the process of engulfing a yolk 
globule. It is doubtful whether either type of 
cell ingests fat in tissue cultures. 
Certain of the cultures, which when living 
contained no loop- or ring-shaped mitochon- 
dria, after the application of different fixatives 
contained in varying numbers swollen, vari- 
cose and ring-shaped mitochondria according 
to the method of fixation employed. The ques- 
tion of fixation is necessarily quite different in 
these cultures, since most of the cells are 
spread out in a thin layer unprotected even 
by plasma from the direct action of any chem- 
ical placed upon them. Nevertheless since cer- 
tain forms of mitochrondria were shown in 
3 Lewis, M. R., and Lewis, W. H., ‘‘Mitochon- 
dria and other Cytoplasmic Structures in Tissue 
Cultures,’’? Amer. Jour. of Anat., 17, 1915. 
SCIENCE 
399 
these cultures,to be the result of the method 
of preservation, it would certainly seem prob- 
able that these same shapes observed by other 
investigators (Dubreuil, 1911 Guilliermond, 
1913),5 were obtained in the same manner. 
In the above observations there was no need 
to resort to fixed preparations, as all the struc- 
tures of the cell were clearly seen, and the 
bright orange-colored droplets could be fol- 
lowed without fear of confusing them with the 
easily distinguishable mitochondria. The fat 
droplets accumulated in the living cell without 
being associated at any time with the mito- 
chondria and without any changes taking 
place in the shape of the mitochondria such as 
have been claimed by other observers (Du- 
breuil 1911,4 Russo 1910,° ete.). 
Marcaret Reep Lewis 
THE AMERICAN MATHEMATICAL 
SOCIETY 
Tue twenty-fifth summer meeting of the 
society was held, by invitation, at Dartmouth 
College, Hanover, N. H., on Wednesday, 
Thursday and Friday, September 4-6, 1918, 
connecting with the meeting of the Mathe- 
matical Association of America, which began 
on Friday morning. The joint dinner of the 
two organizations, on Thursday evening, was 
attended by fifty-six members and friends, 
who were greeted by Dean Laycock in the 
name of the College. At the joint session on 
Friday morning Professor A. G. Webster gave 
an address on “ Mathematics of warfare.” 
The college dormitories were opened for the 
accommodation of the visitors, and meals were 
served in the commons. Headquarters and 
general gathering place between the sessions 
was provided in College Hall, where an in- 
formal reception was held on Wednesday 
evening. A letter of welcome from Business 
4 Dubreuil, G., ‘‘Les nitrochondries des cellules- 
adi peuses,’’ Compt. rend. Soc, Biol., 1911. 
5 Guilliermond, A., ‘‘Sur les nitrochrondries des 
champignons,’’ Compt. rend. Soc. de Biol., 1913. 
6 Russo, A., ‘‘Sui mutamenti che subiscono i 
mitochondrt ed i materiali dentoplasmici dell oocite 
di coniglia in diversi periodi di inanizione,’’ Arch, 
f. Zellf., 4-5, 1910. 
