ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 75 



the escape of protoplasm by the pores through which the flagella pass, 

 this protoplasm being endowed with amoeboid movements, and putting 

 out pseudopodes. The mechanical irritation causes the formation of 

 bladders and pustules on the outer surface of the cell. A direct com- 

 munication is maintained between the internal and the external proto- 

 plasm. 



Similar results were obtained with diatoms and desmids. In Cyclo- 

 tella socialis the individual cells of a colony are connected together by 

 countless threads ; in the interior of the colony, but outside the cell- 

 walls, is a quantity of mucilage and pseudopode-forming protoplasm. 

 The local band-like thickenings of the cell-wall occur partially on the 

 inner, but to a much larger extent on the outer surface of the cell-walls. 



Vibrioids.* — Prof. G. Lagerheim confirms the occurrence of these 

 bodies in vegetable cells discovered by Swingle. He finds thorn in the 

 hyphaa of a fungus. Ascoidea rubesrens, imbedded in the parietal proto- 

 plasm ; in older cells they are often obscured by drops of oil. Their 

 number varies greatly. Their motion consists of a variety of bendings 

 in a plane parallel to the cell-wall. Their form resembles that of a 

 bacillus of uniform thickness ; their length varies between 2 and 20 /x, ; 

 their thickness is about 0*5 //. ; they have rounded ends. They are 

 sharply differentiated from the cytoplasm ; they are slightly refringent ; 

 not doubly refractive ; with very high magnification they appear to 

 consist of a badly defined row of granules. Their microchemical 

 reactions are given in detail. 



(2) Other Cell-Contents (including: Secretions). 



Colours of Flowers.f — Mr. P. Q. Keegan has performed a careful 

 series of experiments for the purpose of deciding between the view of 

 Berzelius that the original colour of anthocyan (the colouring matter 

 of red and blue flowers) is red, and that of Wiesner that it is blue. 

 His conclusion is, on the whole, in favour of the former hypothesis. 

 He believes, however, that there are different stages in the development 

 of the floral pigment. In the lower stages the natural colour is red, 

 whatever the chromogen may be. In the higher stages, on the other 

 hand, the natural colour of anthocyan is blue, or rather— at least with 

 some chromogens — it becomes capable of forming blue compounds with 

 alkalis and certain metallic acids. There also exist chromogens which, 

 except under very exceptional conditions, are incapable of producing 

 a blue pigment. These, in all stages, naturally develope into a red, 

 the brilliancy of which unequivocally attests its real original and proper 

 character. 



Chemical Substances in Plants.} — M. P. van Eomburgh notes the 

 occurrence of the following substances in the vegetable kingdom. Acetone 

 is probably widely distributed, and was detected in Hevea brasiliensis, 

 Manihot Glaziovii and utilissima, Phaseolus lunatus, and other plants. 

 Methyl salicate is apparently also a substance of wide distribution in the 

 vegetable kingdom. The presence of hydrocyanic acid was determined 



* Ofv. k. Vetensk. Akad. Forhandl., lvi. (1899) pp. 557-6t (1 fi<r.) (German). 

 Cf. this Journal. 1898, p. 316. t Nature, Ixi. (ISQ9) pp. 105-6. 



X Ann. Jard. Uot. Buitenzorg, xvi. (1899) pp. 1-16. 



