384 BOTANICAL GAZETTE [ocToBER 
successful with the white ones, and found further that the eS begin 
to disintegrate in the course of 30 minutes after the mount is m 
n a third paper‘ dealing with alterations of the rete hs finds that 
“the mitochondria are the most fragile elements of the cell, and it is through 
them that the first signs of degeneration and the first symptoms of trouble due 
to osmotic changes are manifested.” The alteration consists of the transforma- 
tion of the mitochondria into vesicles having the aspect of vacuoles and giving 
the cytoplasm an alveolar appearance. This, the author remarks, is interesting 
when we think of BUrscut1’s alveolar structures. 
In a fourth paper’ dealing with the fixation of cytoplasm, he finds that 
from the point of view of their action on the chondrium fixing agents may be 
grouped in three classes: (1) Gen Mann’s, Zenker’s, and Carnoy’s fluids 
all disturb the structure of the cytoplasm and destroy the mitochondria; 
(2) picric acid, mercuric chloride, Co and strong Flemming’s generally 
Regaud’s, and Flemming’s with only a trace of acetic acid are the fixing agents 
commonly used for fixing mitochondria and the cytoplasm as nearly like living 
as possible. In general it is those reagents which contain alcohol or acetic 
acid which alter the mitochondria most 
Mortter® has published a valuable contribution to the study of mito- 
chondria, not only in the new facts he has revealed, but more especially in the 
account of his methods, which will enable workers much less qualified to take 
up studies in this interesting field. In the main he used Flemming’s fluid, 
with very much reduced amounts of acetic acid for a fixative and iron haema- 
toxylin and crystal violet for stains. For material he used root tips of Pisum 
sativum, Zea Mays, and Adiantum pedatum; the thallus of Marchantia poly- 
morpha, Anthoceros, and Pallavacinia; seedlings of Pinus Banksiana; leaves 
of Elodea canadensis; and certain algae 
He finds that root tips of Piswm furnish excellent material for a study of 
the primordia of plastids and their transformations. Mitochondria-like 
structures are very numerous, such as rods of various lengths and thicknesses, 
straight, variously curved and bent, and also numerous smaller granules and 
slender delicate rods. Leucoplasts develop from the larger structures, but the 
smaller ones do not form plastids. Although these structures all give the same 
histochemical reactions, the term chondriosome (mitochondrium) is reserved 
for those smaller structures which do not form plastids. The former he calls 
“plastid primordia.” Zea Mays is similar in all essentials to Pisum. In 
Marchantia the “plastid primordia” are more readily distinguished from the 
4 GUILLERMOND, A., Loc. cit. 164:609-612. 1917. 
5 
, Loc. cit. 164:643-646. 1917. 
® Mortier, D. A., Chondriosomes es the primordia of chloroplasts and leuco- 
plasts. Pine ‘Bot tany ya: gI-114. pl. 1 
