292 THE AMERICAN NATURALIST. [VoL. XXXII. 
the case in most colleges, a very small percentage only of the students 
of science are likely ever to have the opportunity to devote their 
lives to research, T: 
A Guide in Vegetable Physiology. — Professor Arthur of Pur- 
due University has issued in pamphlet form an outline for thirty- 
five laboratory exercises in vegetable physiology,’ which are intended 
to guide the student in manipulation while avoiding the provision of 
information as to the purpose of the experiments or the deductions 
to be drawn from them. 
w Digestion of the Albumen of the Date. — M. Leclerc du Sablon, 
in the Revue Générale de Botanique for Nov. 15, 1897, publishes a 
paper on the digestion of the “albumen” of the date, in which it is 
shown that not only is this albumen incapable of digesting itself, but 
that the diastases secreted by the cotyledon, which attack the cellu- 
lose, do not penetrate into the albumen, their action appearing only 
in the region of contact between the cotyledon and the albumen, only 
the enzyme which leads to the production of fatty acid passing from 
the cotyledon into the albumen, where it begins the digestion of the 
fatty reserves. 
Experiments with Etiolated Leaves. —In a paper published in 
No. 107 of the Revue Générale de Botanique, Palladine shows that 
when etiolated leaves free from carbohydrates are placed on the 
surface of various solutions, saccharose, raffinose, glucose, fructose, 
maltose, glycerine, galactose, lactose, and dextrine favor the forma- 
tion in them of chlorophyll, while inulin and tyrosin produce no 
effect, and mannite, dulcite, asparagine, alcohol, and some other 
substances either retard or completely prevent the formation of the 
pigment. 
Life History of Ranunculus.— To the Botanical Gazette for 
February, Prof. John M. Coulter contributes an addition to the life 
history of Ranunculus, embodying the results of the study of a 
number of research students at the University of Chicago. The 
results appear to justify the conclusion that while it is comparatively 
easy to obtain a definite sequence in the development of structures 
when the facts are few, definite sequences seem to disappear as facts 
multiply; a conclusion which may be paralleled in nearly or quite all 
1J. C. Arthur, Laboratory Exercises in Vegetable Physiology. Lafayette, Ind., 
1897. Kimmell & Herbert. 
. 
