BOTANY. 839 



hydrojiliytes, through mesophytes, to xerophytes. In a general way, the hniit of 

 available water within the plant coincides with the physical conditions of its habitat. 



Herbaceous plants, both annuals and perennials, when affected by slow drought 

 usually die in the following manner: The older leaves of the plant perish first, the 

 younger ones living to the last. The finer roots die first, then the coarser ones, 

 finally the stem, and last of all the growing point of the stem, or if the plant is a 

 flowering one the immature fruit. Trees, shrubs, and perennial herbs lose their aerial 

 organs first, the roots usually being the last part of the plant to die. Bulbous and 

 tuberous plants, even when immature, form their ImiDis and tu])ers quite rapidly 

 when caused to die by drought. 



Influence of the awns of grasses, 8. Treyakov (Kliozyaene, 1D02, No. 6, pp. 188- 

 I'Jl; (ihx. Ill /Inn: Opiiiii). Agraii. {.Tour. Expt. Lcnuhv.'], S{1903), No. 2, pp. 239, 240). — 

 The influence of the awns on the development of the grain in red winter bearded 

 wheat was studied by the author at the Poltava experiment field. Two i)lats were 

 selected, in one of which all the awns were removed from the spike as soon as they 

 appeared, while upon the other they were allowed to remain. The ripening began 

 2 days earlier in the case of those spikes deprived of their awns. The yield of grain, 

 as well as the ash analysis, is shown, from which the conclusion is drawn that the 

 absence of awns is accompanied by a smaller-sized grain and by less weight. The 

 grain from the awnless spikes was richer in ash but poorer in nitrogen and phos- 

 phorus. Comparisons were made with the figures obtained in this experiment, and the 

 results of growing bearded and beardless varieties of wheat were found analogous in 

 each case. By comparing the average yields of awned and awnless wheat for a num- 

 ber of years the author concludes that awned varieties, under the conditions of cul- 

 tivation at the experimental field, gave smaller yields of grain, but the individual 

 grain possessed a higher absolute weight, and the fluctuations of the bearded wheats 

 are less than those of the lieardless varieties. — r. fikkmax. 



Influence of the fluctuation of temperature on the respiration of seeds 

 and embryos of wheat, Kakchevski {Mnn. Warsaw Univ., 9 {1901), pp. 114; aba. 

 ill Zlnn: OjniKn. Arjr'm. [Jour. Expt. Land)/:'], 3 {1903), No. 2, p. 241). — The investi- 

 gations here reported were conducted to ascertain how the seeds and embryos of 

 wheat are affected by being subjected to elevated temperatures. The subjects experi- 

 mented upon were placed for 24 hours in water before the determination of the car- 

 bon dioxid exhalation was begun. As a result of 24 experiments the author 

 concludes that the energy of carbon dioxid respiration is 12 times as great in the 

 case of the embryos as in the seeds themselves. The preliminary drying of the 

 embryos at temperatures of 62° for 24 hours does not exert any appreciable influ- 

 ence on the respiration. If heated to 70° C. a reduction is ol)served, and at 98.5° 

 C. there is a complete cessation of the exhalation of carbon dioxid and death of the 

 embryo. With the seeds no change takes place ev-en when dried up to temperature 

 of 91° C. A rapid fall in the respiration of carbon dioxid begins if dried for 24 hours 

 at 98 to 105°, and at 112° death results. These figures were obtained with seeds and 

 embryos which were subjected to elevated temperature in a dry condition. If the 

 same temperatures are attained in water, the death point is found to be considerably 



lower. —p. FIREMAN. 



Influence of light on the respiration of some of the lower fungi, N. A. 

 Maximow {Centbl. Bakt. u. Par., 2. Abt., 9 {1902), Nos. G-7, pp. 193-205; 8, pp. 261- 

 372, fic/s. 2, flgms. 18). — The results of a prolonged series of experiments with A.sper- 

 giUiisniger, Mncor slohmifer, Penicillinm sp., Oidium lad is, Micrococcus jtrodigiosus, and 

 Proteus vulgaris are given. The organisms were grown in culture media, and the effect 

 of light and darkness on the carbon dioxid production was determined. The experi- 

 ments with Aspergillus niger and Mucor stohnifer are reported at considerable length. 

 It was found in the case of Aspergillus that the influence of light on respiration was 

 dependent upon the age of the fungus and the conditions of nutrition. With young. 



