BOTANY. 1007 



are capable of absorbing and utilizing glucose and invert sugars. The 

 cultures were made in sterile liquid media and served to show under 

 the conditions of the experiment that maize will grow for several 

 weeks in an atmosphere deprived of carbon dioxid. Check plants cul- 

 tivated without glucose under bell jars gained little or nothing in dry 

 weight during the experiment. In darkness and the presence of glucose 

 the increase in dry weight of maize plants was considerably less than 

 in the light, although still appreciable. Maize, as is shown, is able not 

 only to reduce sugars but also saccharose, dextrin, and starch. The 

 roots of wheat, maize, and peas are able to invert cane sugar sufficient 

 for their necessities. The digestion of dextrin and starch by the roots 

 of maize takes place slowly, and only very small quantities of glucose 

 can be recognized in the culture; nevertheless these two substances 

 may be taken up in appreciable quantities, two plants of maize having 

 consumed in 34 days about 0.5 gm. of starch. 



Following the same system of sterile cultures, the author shows that 

 glucose may be absorbed by the roots of different plants and serve 

 directly for synthesis of starch. Plants of mercury, peas, common 

 groundsel, tropreolum, and sunflower were grown for some time in dis- 

 tilled water in darkness until their starch was used up. Their roots 

 were then placed in a solution of glucose and exposed to sunlight in 

 an atmosphere deprived of carbon dioxid. After G hours at a tem- 

 perature from 20 to 25° C. the leaves were found rich in starch, while 

 the check plants in distilled water did not contain any. Similar results 

 were obtained with ivy, calendula, and round-leaved mallow by simply 

 watering the soil in which the plants were grown with a solution of 

 glucose. 



In the different experiments it was observed that the starch first 

 appeared in the cells surrounding the stomata, and in these cells it was 

 last to disappear in the darkness. 



Summing up his conclusions, the author states that from his studies 

 there must be two methods of carbon assimilation — one the ordinary 

 chlorophyll function and the other the absorption of certain chemical 

 compounds after their digestion by the roots. This last method is 

 entirely distinct from the carbon nutrition of fungi and plants without 

 chlorophyll. 



Investigations on the carbohydrate reserve material in bulbs 

 and tubers, Leclerc du Sablon (Rev. Gen. Bot., 10 (1898), 2fo. 117, 

 pp. 353-369; 118, pp. 385-403; 119, pp. 447-482; 120, pp. 519-538, figs. 

 23).— Studies are reported on the carbohydrate reserve material in the 

 bulbs and tubers of Ophrys aranifera, tulip, hyacinth, lily, colchicum, 

 potato, Ranunculus bulbosus, arum, iris, Ficaria ranunculoides, arti- 

 chokes, dahlia, onion, asphodel, and Stachys tuberifera. For the most 

 part the reserve organs studied are biennial. During the first year 

 they form their reserves for utilization during the second year, and 

 between these two periods there is a resting stage. 



Among the plants investigated it was found that the carbohydrate 



