CURRENT LITERATURE 
MINOR NOTICES 
Mosses and ferns.—A third edition of CAMPBELL’s well known textbook! 
has appeared. The body of the text is the same as in the second edition of 
1905, the new material being added in the form of an appendix, under the 
corresponding chapter headings. In addition to numerous contributions by 
other investigators, the appendix contains noteworthy results of the author in 
his investigations of tropical liverworts and ferns. The bibliography is com- 
pletely recast, including 772 titles, distributed among 336 authors. The 
author has rendered an important service to morphologists in bringing up to 
date, and in convenient form, our knowledge of these great groups.—J. M. C. 
NOTES FOR STUDENTS 
Mitochondria.—GUILLIERMOND has published a number of short reports 
dealing with the results of his investigations on the nature and function of 
mitochondria. In a paper? dealing with the origin of chromoplasts and pig- 
ments, he finds that chromoplasts are formed from mitochondria, more espe- 
cially from the elongated forms called chondriocontes; and that pigments of the 
xanthophyll and carotin groups are elaborated either (1) directly by the mito- 
chondria, or (2) by chromoplasts which arose from mitochondria, or (3) by 
chromoplasts resulting from a metamorphosis of chloroplasts which in turn 
arose from mitochondria. Added interest is given because of the fact that in a 
great many plants the process can be observed in the living material under the 
microscope. Both granular and crystalline pigments have the same origin. 
Epidermal cells from petals of Iris germanica, Tulipa suaveolens, Tropaecolum 
majus, and young fruits of Arum maculatum, Asparagus officinalis, and numer- 
ous others furnished the material for this study. 
In a later paper’ dealing with the chondrium of Tulipa, he reports that the 
mitochondria are easily visible in the living material under the oil immersion 
lens. Epidermal cells from petals are used. The mitochondria are long, thin, 
and undulate, although smaller granular and rod mitochondria are present. 
Material is at its best just about the time the flowers first open. The reviewer 
has verified these observations with the yellow-flowered variety, but was not 
* CampBett, D. H., The structure and development of mosses and ferns (Arche- 
goniatae). 3d ed. 8vo, pp. 708. figs. 322. New York: Macmillan Co, 1918. $4.50. 
2 GUILLIERMOND, A., Compt. Rend. Acad. Sci. 164:232-235. 1917. 
, Loc. cit. 1642407-409. 1917. 
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