A474 
the nucleus extends into the neck, where it 
undergoes direct division, one-half remain- 
ing in the mother cell, while the other half 
enters the bud; and that, in the process of 
spore formation, the nucleus breaks up into 
two, and then into four, nuclei by a very 
simple process of karyokinesis. Some of 
the phenomena observed appeared to be 
new in the history of nuclear division and 
require more extended observation, but the 
paper as a whole offered an important ad- 
dition to our knowledge of cell life, and 
proved to be particularly opportune in con- 
nection with the joint discussion on the 
cell held by the botanists and zoologists. 
The efforts originally made by Hartig, 
and later by Brefeld, to study the develop- 
ment and action of wood-destroying fungi 
as represented by Stereum hirsutum, met with 
failure either through lack of pure cultures 
or imperfect methods of treatment. Pro- 
fessor Ward presented an account of his 
own recent studies of this plant, in which 
he employed blocks of sterilized wood, 
whereby he succeeded in securing a perfect 
fructification and observing the plant in all 
stages of development. The details of the 
progressive destruction of the woody tissue 
were also dealt with, and it was shown that 
the lignified structure gradually yielded to 
the action of the fungus and passed into the 
condition of cellulose-like bodies, giving the 
characteristic iodine reaction, before final 
consumption. The paper was illustrated 
by a series of beautifully prepared lantern 
slides, from photographs and drawings. 
Professor Penhallow contributes the re- 
sults of recent studies of the species of 
Picea occurring in the eastern United 
States and Canada, in the course of which 
he showed that the red spruce which had 
been abandoned as a distinct species since 
the time of Pursh, and regarded as a form 
of the black spruce, must once more be re- 
stored to the status of a valid species as 
maintained by Lawson and later by Brit- 
SCIENCE. 
[N. 8. Vox. VI. No. 143. 
ton. He also pointed out that there is a 
well defined variety of the white spruce, 
hitherto unrecognized, the chief character- 
istics of which are to be found in the 
strongly glaucous, rigid, often broad and 
cuspidate leaves, and distinctly fetid odor 
which has long led lumbermen and others 
to designate it by the name of ‘Cat’ or 
‘Skunk Spruce.’ He proposes to distin- 
guish it by the variety name of fetida. 
Mr. Francis Darwin gave a preliminary 
account of a new method of investigating 
the behavior of stomata, in which he de- 
tails the use of a new form of hygroscope 
made of thin sheets. of specially treated 
horn or ‘Chinese sensitive leaf.’ One 
end of a narrow strip is secured to the 
lower surface of a block of cork, and the 
angle to which the free end rises becomes 
the index of transpiration. In application, 
if the leaf have stomata on the under sur- 
face only, the index of the hygroscope ap- 
plied to the upper side remains at zero, 
while on the lower side it instantly rises to 
an angle varying with the condition of the 
stomata. If these organs are widely open, 
the angle will be 30°-40° to a horizontal 
line; if the stomata are closed, the reading 
will be zero on both surfaces of the leaf. 
With this instrument a number of well 
known facts in the physiology of the sto- 
mata can be easily demonstrated. 
Mr. H. J. Webber, of the U. S. Depart- 
ment of Agriculture, detailed the results of 
recent studies on the spermatozoids of 
Zamia. By means of a series of beauti- 
fully prepared sections he demonstrated 
the occurrence of unusually large sperma- 
tozoids, which, together with their flagelle, 
may be seen without difficulty with an or- 
dinary pocket lens. The paper throws 
new light upon our conception of the sexual 
elements of the Gymnosperms, and will 
doubtless serve as a powerful incentive to 
greater activity in the study of this group 
of plants. 
