1910] CURRENT LITERATURE "231 
various carbohydrates deflected pollen tubes, and in 1899 Liprorss reported that 
they were responsive also to certain proteins. In the last ten as with the ex- 
ception of a few papers by the same author, nothing has app on the responses 
of pollen tubes. Now Liprorss, who has been prosecuting his researches year 
after year, in the short periods available each season for any particular plant, 
presents the results in detail.t* First he discusses the effect of various chemical 
agents upon the germination of the pollen. In the section on proteo-chemotro- 
pism, Lrprorss lists the large number of proteins of various groups that have 
yielded definite results. In general it may be seen that the pollen tubes are indif- 
ferent to cleavage products of proteins, and are harmed by the albumoses and 
peptones tried. On the contrary, to the albumins, nam nucleo-albumins, 
coagulated proteins, and glycoproteins, nineteen in all, the tubes respond by 
positive curvatures. The nucleo-proteins differ much, some being attractive, 
is less than 5 min. , and for Narcissus Tazetta and Tradescentia virginica less than 
2-3 min. The limninal value of the concentration was difficult to determine. 
. the case of diastase with Vallota purpurea it was about o.1 per cent. Only 
he case of apochemotropism with proteins was observed (Scilla campanulata 
ma diastase), and as this could not be confirmed by later experiments it was 
Possibly due to some impurity of the diastase used. Proteo-chemotropism has 
been found in 1 3 families of monocotyls and 42 families of dicotyls, so that it may 
be considered as of general occurrence in angiosperms. 
Saccharo-chemotropism was not investigated extensively by Liprorss, but 
his limited observations, combined: with those of MryosHt, make it probable that 
responses to various carbohydrates are also secatil among angiosperms. Osmot- 
ropism was clearly shown by some tubes, and the author promises a later paper 
on this subject. Ina special part, an appendix to the body of the paper, there are 
details regarding all the species of pollen studied, as to favorable conditions for 
germination and the responses obtained. These furnish useful details for labora- 
tory directions in employing these experiments in instruction.—C. R. B. 
Persistence of characters in Aspergillus. —KoMINAMI" has investigated the 
Persistence of characteristics induced in Aspergillus niger by subjecting that mold 
to unusual cultural conditions, in this case strong solutions of common salt. The 
conidia used in the experiments were obtained from three strains: (1) from cul- 
tures on normal nutrient media; (2) from cultures grown for one generation on 
hutrient solution containing 6 per cent. of salt; and (3) from cultures grown for 
bee a 
tas s, B., Untersuchungen iiber die pee RP der Pollenschiiuche. 
I. Der Chenoa Zeit. Bot. 1:443-496. pl. 3. 19 
2 Kommnam, K., iene me iene iiber Schimmelpilze. 
fa Coll. a Tokyo 2721-33. pls. 3. 
