210 BOTANICAL GAZETTE [MARCH 
forms an haustorium. Finally, the protoplasmic contents of both haustoria 
become transformed into a network of cellulose threads which in case of the 
upper haustorium form a plug eeeetially closing the micropyle. The sac is 
surrounded by a jacket or “‘tapetum’”’ which is even more conspicuous than 
in the Compositae.— CHARLES J. CHAMBERLAIN. 
THE FUNCTION of latex, so often in past years a motive for investigation, 
has again been made a subject for study. Gaucher” gives a historical sum- 
mary of the two chief views, excretory and nutritive, from the time of Trécul 
to the present. The author gives no new theories, but presents a large num- 
ber of facts which favor the nutritional function, very much as presented by 
Haberlandt. The substances contained in latex, the connection between the 
latex tubes. and the palisade, and the reciprocal relations between latex tubes 
and conductive parenchyma are all studied, and Gaucher in these cases con- 
firms and extends Haberlandt’s observations. In one instance he finds a ring 
or festoon of chlorophyll cells arranged about a latex tube. 
Parkin * has studied the latex in rubber plants of Ceylon, and holds a some- 
what intermediate view. While he regards the proteids of latex as probably 
nutritive, he does not so regard the starch, unless perhaps the latter aids in 
the nutrition of the latex tubes themselves. The author finds that the latex 
flows far less abundantly at the first tapping than subsequently, showing an 
apparent adaptation. Mane vepards the chief function of latex to be water 
storage.—H. C. Cow. 
SOME VALUABLE CONTRIBUTIONS to the literature of forest distribution 
have been made recently by the United States Geological Survey. This 
report is under the supervision of Henry Gannett, chief of the division, and 
is a companion volume to a similar one published last year. It contains 
special considerations of the Pike’s peak, Plum creek, and South Platte 
reserves by John G. Jack; White river plateau timber land reserve by George 
B. Sudworth; the Flathead forest reserve by H. B. Ayres; and the Bitter- 
root forest reserve by John B. Leiberg, Topographic features, soil condi- 
tions, climate and rainfall, forest conditions, fires, and lumbering are some 
of the topics treated in these reports. A large number of plates, including 
both maps and reproductions from photographs, are incorporated in the 
volume, and a portfolio containing topographic eg showing distribution of 
timber areas presents the subject in a graphic w 
If the department would but i incorporate in its eweaiiee: geological and 
physiographical atlases an additional topographic map showing the distribu- 
tion of forest and other floral areas, including descriptions of the edaphic 
and climatic conditions, it would add much to their educational, economic, 
Ann, Sci. Nat. Bot. VIII. 12: 241-260. 1900. Ann. Bot. 14 : 193-214. 1900. 
3Twentieth Annual Report, U.S. G. S., Part V. Forest reserves, pp. xviii + 498. 
pls. 159. 1898-9. 
