1916] AGRICULTURAL BOTANY. 523 



Experiments with catalytic manures, I, Giannosi (Italia Agr., 52 {1915), 

 No. 10, pp. 455-458; abs. in Internat. Inst. Agr. [Rome], Mo. Bui. Agr. Intel, 

 and Plant Diseases, 6 {1915), No. 12, p. 1596) .—Field experiments with hemp 

 conducted at the Royal Agi-icultural College at Bologna, Italy, to determine the 

 influence of catalytic fertilizers containing 7.32, 9.32, and 7.08 per cent of 

 manganese tetroxid, when applied in amounts varying from 220 to 305 lbs. 

 per acre, are reported. 



The best yield was obtained on a control plat and the poorest on a plat 

 receiving the catalytic manure, but the differences in the results from different 

 plats were so small as to be within the limits of experimental error. It is 

 concluded that the catalytic manure had no appreciable effect. 



Composition of some oil cakes used as fertilizer in Tonkin [Indo China], 

 Bloch {Bui. Econ. Indochine, n. ser., 18 {1915), No. 115, pp. 757, 758). — Analy- 

 ses of ten samples of oil cake are reported, showing contents of nitrogen varying 

 from 1.02 to 4.76 per cent, potash in four cases varying from 0.042 to 0.3 per 

 cent, and phosphoric acid in four cases varying from 0.203 to 1.955 per cent. 



AGRICULTTJRAL BOTANY. 



Starch congestion accompanying certain factors which retard plant 

 growth, B. L. Haetwell (Rhode Island Sta. Bui. 165 (1916), pp. 23).— It hav- 

 ing been observed that accumulation of starch in potato vines followed a de- 

 ficiency of available potassium in the soil, a series of investigations was under- 

 taken to determine whether the deficiency of the element in question might in- 

 hibit cell development, causing less demand for starch, or whether potassium 

 was essential as an activator of diastatic action. 



As a result of the investigations it was found that an accumulation of starch 

 seems to be correlated in general with conditions which cause a retardation of 

 growth. The different factors which result in the accumulation of starch in 

 the above-ground portion of the plant do not appear to interfere with photo- 

 synthesis, but it is thought that they may have some influence on subsequent 

 metabolism. 



Potato tuber production above ground, V. Vilikovsk-s- (YSstnik 5. Sjez. dea. 

 L6k. Pfir., 1915, p. 412; ahs. in Bot. Ccntbl., 129 (1915), No. 15, p. S72).—The 

 author supports the view that the formation of tubers on the potato plant above 

 ground is due to the excessive storing of starch. This is to be regarded as not 

 necessarily pathological but as the result of producing starch faster than it can 

 be removed to its more usual situation in the underground tubers. 



The origin of anthocyanin pigments, A. Gxjttj.tkrmond (Compt. Rend. Acad. 

 Sci. [Paris], 161 (1915), No. 19, pp. 567-570). — The author discusses the two 

 main hypotheses supported by different investigators regarding the origin of 

 anthocyanin, the one being that anthocyanin pigments result from the trans- 

 formation of colorless phenol compounds previously formed in the cells and the 

 other that these pigments are formed in place directly as colored products. He 

 agrees with the later views of Combes (E. S. R., 32, p. 824) in holding, as the 

 result of his own investigations (E. S. R., 35, p. 333), that while anthocyanin 

 is in a large number of cases found in the mitochondial body, it may under dif- 

 ferent circumstances be derived also from the transformation of colorless phenol 

 compounds previously formed in the mitochondria and then dissolved in the 

 vacuolar liquids. 



Recent observations on pollen formation in certain monocotyledons, L. 

 GuiGNAED (Compt. Rend. Acad. Sci. [Paris], 161 (1915), No. 21, pp. 623-625).— 

 Reporting further observed exceptions to the two general modes of pollen for- 

 mation (E. S. R., 34, p. 525), the author states that the Orchidacese may now be 



