PLANT PHYSIOLOGY 221 



in those stored at 40° F. His results thus agree well with those 

 of Overholser and Taylor. 



Changes taking place during the ripening of tomatoes have 

 been examined by C. E. Sands (" The Process of Ripening in 

 the Tomato, considered especially from the Commercial Stand- 

 point," U.S. Dept. Agric. Bull., 859, 38 pp., 1920). He finds 

 that in general throughout the ripening period the percentage 

 of water, acids, and sugars increases, whereas the proportion 

 of total nitrogen, starch, pentosans, " crude fibre," and ash 

 constituents decreases. Thus while sugars increased from 

 25-7 per cent, in young fruit (14 days old) to 48 per cent, in 

 ripe friut, starch decreased in the same time from 15-8 per 

 cent, to 2*7 per cent. Similar results were obtained by F. L. 

 Dominguez {Ann. Rep. Insular Exper. Sta. Dept. Agric. and 

 Labour, Porto Rico, 105-8, 191 8) with regard to the chemical 

 changes in ripening grape fruit. 



ZOOLOGY. By Reginald James Ludford, Ph.D., B.Sc. (Lond.), 

 University College, London. 



Protozoology . — A new ciliate, Balantidium blattarum, which 

 occurs as an intestinal parasite in the common cockroach, is 

 described by E. Ghosh in Parasitology, vol. xiv, No. i. This 

 protozoon was found in the intestinal contents of cockroaches 

 collected at Calcutta, and the writer states that it is com- 

 paratively rare in its distribution. 



B. L. Bhatia continues his descriptions of fresh-water 

 cihate protozoa of India in the Journ. Royal Micr. Soc, March 

 1922. Altogether forty-one species of ciliates have been 

 described by this investigator, and only two of these have 

 been recorded by previous investigators in India. 



Cytology. — In a paper on " Surface Tension and Cell 

 Division "' {Q.J.M.S., June 1922), J. Gray compares the 

 surface-tension phenomena of dividing cells with oil drops 

 during fusion and fission. He concludes that the cleavage 

 furrow is the result of an equilibrium estabhshed between the 

 movement of protoplasm induced by elongation of the axis 

 of the cell due to separation of the asters and the surface 

 tension at the cell surface. " There is no necessity to postu- 

 late regions of differential surface tension at the poles or 

 equator of the cell." 



" The Gametogenesis of Saccocirrus " is described by J. 

 Bronte Gatenby in the Q.J. M.S., March 1922. This is the 

 first account published of the cytoplasmic organs during 

 oogenesis in this Archi-annelid. The mitochondria and 

 Golgi apparatus apparently play no direct part in yolk for- 

 mation as occurs in some of the types previously described. 



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