Arontlily Microscopical"! / QQ \ 



Juunial, Feb. 1, 1S70. J I, ^'^ / 



PEOGKESS OF MICROSCOPICAL SCIENCE. 



The Cause of Variegation in the Leaves of Plants. — Practical 

 botanists are well aware of two things: (1) that a rage now exists 

 for plants the leaves of which are blanched in parts; and (2) that 

 whatever the nature of this blanching, which sometimes appears spon- 

 taneously, any plant may be made variegated by inoculating into 

 it the sap of one which is variegated already by means of engrafta- 

 tion. But the cause of this phenomenon has been sought by M. 

 Edouard Morren who, in a most interesting paper on the whole subject, 

 recently read before the Belgian Academy, tries to explain it. Dr. 

 Morren recites the experiments of others, and he seems to imply 

 that the affection, for such there is reason to regard it, is the re- 

 sult of the presence of minute corpuscles which have no green colour 

 like the ordinary corpuscles. The etiolated parts, he says, are not 

 altered by carbonic anhydi'ide (?), and they enclose " imperfect granu- 

 lations deprived of green colouring matter." Dr. Morren refers to 

 the recent able experiments of our countryman, Dr. Maxwell T. 

 Masters, on Jasminium officinale, and his paj)er is of interest because, 

 as it seems to us, it opens up a field in which every microscopist 

 may do some good work. — Vide L'Institut, January 19. 



The Movement of the Chlorophyll Corpuscles. — At the meeting of 

 the French Academy of Sciences on the 17th of January, a note was 

 presented from M. Eose relative to M. Prillieux's last researches on 

 the influence of light on plants. The author has found that the light 

 does not affect each individual corpuscle so as to cause it to move, 

 but operates on the material siu-roimding a number of corpuscles, 

 and by influencing it causes the corpuscles to move. — Vide Comptes 

 Benchis, January 17. 



TJie Constitution of the Ovum in Sacculince. — M. Balbiani replies to 

 M. Ed. Van Beneden on this point in a paper read before the French 

 Academy. He considers that he has proved that the small clear eleva- 

 tion placed on one of the points of the surface of the egg of theSacculinae 

 is not the cicatricule as supposed by M. Gerbe, but is really a small 

 rudimentary ovule, adherent to the matvu-ed one, and which is subse- 

 quently detached from it. " M. Ed. Van Beneden," says M. Balbiani, 

 " thinks that after its separation the minute ovule remains in the 

 interior of the reproductive organ to give birth to two daughter-cells, 

 which become adherent to each other, and one of which, in its turn, 

 becomes an egg. According to his view, a single cell would by suc- 

 cessive sub-divisions give rise, without ceasing, to new ova. This 

 explanation is not only improbable but is actually in contradiction 

 with the direct observation of facts. According to my observations 

 upon the ovary in the fresh state on specimens hardened in spirits 

 of wine, and from which sections had been made in various direc- 

 tions, this is how the thing really takes place : — On a point of one of 

 the ramifications of the ovary a small cell appears at first by a process 



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