140 THE JOURNAL OF INDIAN BOTANY. 



important. Doubtless protoplasm may change from one condition to the other 

 in response to changing conditions. 



But protoplasm certainly is not so simple as a simple two-phase colloidal 

 system. The present theory of colloids allows for the possibility of one 

 colloidal system containing other more or less differentiated systems. " The 

 cell must at least be conceived as a complex of such colloidal systems, some 

 possibly simple two-phase systems . . . some polyphase . . ." Such 

 a conception would account for the presence of localized areas in which 

 special processes are carried on. The surface tension membranes between 

 the various constituents would hinder diffusion between the different regions 

 of the cell, would make possible the maintainance of the various structures 

 and organs of the cell which the microscope reveals, and would permit 

 widely diverse processes to go on simultaneously within the same cell. 



Genetics and the structure of protoplasm. Some sort of serial arrangement 

 of hereditary factors in the chromosomes theoretically appears best to fit 

 the facts of chromosome reduction and segregation of factors. From a few 

 accurate records of size and volume of chromosomes, and from measure- 

 ments that have been made of the size of various molecules, there appears 

 to be plenty of room in chromosomes for a number of molecules " equal to 

 the most extreme demands of the factorial hypothesis, if each factor can be 

 represented by a single molecule or even a group of molecules." 



Winfield Dudgeon. 



Mottier, David M. Chondriosomes and the primordia of chloro- 

 plasts and leucoplasis. Annals of Botany XXXI 1 {1918) pp. 91-114. 



1 pi. 



Chondriosomes (mitochondria) were discovered in plant cells by Meves 

 in 1904. Since then a great deal of research has led to the conclusion that 

 they are very numerous in the cytoplasm ; that they are practically univers- 

 ally present in plant cells ; and that they are almost certainly permanent 

 cell organs, being transmitted from one cell generation to the next along with 

 the cytoplasm. Some have claimed that they become transformed into plastids 

 of various kinds, while others hold that chondriosomes and the bodies which 

 develope into plastids are quite distinct. It has been found that some of the 

 most commonly used killing and fixing reagents, especially acetic acid, des- 

 troy chondriosomes, and this fact probably accounts for their late discovery. 

 Mottier used as a fixing solution 



1% chromic acid 17 cc. 



2% osmic acid 3 cc. 



glacial acetic acid 3 drops 



and stained with either a modification of Benda's crystal violet method or 

 iron- alum-haematoxylin. He worked with root tips of Pisurn sativum, Zea 

 mays, and Adiautum pedatum; thalli of Marchantia polymorpha, Anthoceros 

 laevia, and Pallacicinia ; seedlings of Pinus Banksiana ; and stem and leaves of 

 Elodea> canadensis. Pisum proved to be the most satisfactory material for 

 study. 



When properly fixed and stained, the meristem cells of the root-tip 

 of Pisum show a large number of small but quite conspicuous bodies 

 of two distinct kinds scattered through the cytoplasm : some are larger, 

 straight or variously bent rods of varying length and thickness ; others 

 are very small granules occurring singly or in chains, or delicate slender 



