No. 3, December, 1920] CYTOLOGY 141 



collected in December, :i fusion was discovered not only between these two protoplasts but 

 also between their nuclei. The behavior of the chromatin could not be clearly seen, but the 

 chromatic material from the two nuclei seemed to be more or le - intermingled. Cases were 

 found where the ventral canal cell hud disintegrated; in other instances the eg^ had disinte- 

 grated and the ventral canal cell remained functional. — E. It'. Sinnott. 



980. Carter, Nellie. Studies on the chloroplastids of Desmids III. X. The chloro- 

 plasts of Cosmarim. Ann. Botany 34: 265-286. 1920.— See Bot. Absts. 6, Entry 1191. 



9S1. Conklix, E. G. The mechanism of evolution. Sci. Monthly 10: 496-515. 1920.— 

 See Bot. Absts. 5, Entry 1987. 



982. Dangeard, Pierre. Sur devolution du systeme vacuolaire chez les Gymnospermes. 

 [The development of the vacuoles in Gymnosperms.] Compt. Rend. Acad. Sci. Paris 170: 

 474-477. 8 fig. 1920. — Larix europca, Taxus baccata, and Gingko biloba were studied in liv- 

 ing condition by means of intravital stains. Vacuomes, spheromes and plastidomes may be 

 found in the same living cell. An especial study is made of the vacuome in which metachro- 

 matin exists in young cells as grains which enlarge and fuse into a network which may be 

 spread throughout the cytoplasm. From this network are later formed the vacuoles. — C. H. 

 and W. K. Farr. 



983. Dangeard, P.-A. Plastidome, vacuome et spherome dans Selaginella Kraussiana. 

 [Plastidomes, vacuomes and spheromes of Selaginella Kraussiana.] Compt. Rend. Acad. Sci. 

 Paris 170: 301-306. 1 pi. 1920. — The author, as in earlier writings, distinguishes three types 

 of structures which are usually referred to as mitochondria or chondriosomes: namely, plas- 

 tidomes, vacuomes and spheromes. All are stained black by iron haematoxylin. Selaginella 

 affords excellent material for the study because of the few large chloroplasts. The chloro- 

 plast arises from a small band lying appressed to the nuclear membrane, which stains deeply 

 with iron haematoxylin and divides just prior to cell-division. Successive divisions of this 

 band, which is called the "mitoplast," give rise to several chloroplasts. Mitoplasts are 

 found in meristematic tissue, young leaves, cortex of the stem, vascular tissue, root tips, and 

 in the primordia of sporangia. — In the vacuoles are metachromatic corpuscles which com- 

 pose the vacuome. They react to the Regaud stain in the same way as do the mitoplasts. 

 As the vacuoles fuse in the maturing of the cells the vacuomes may remain single or group 

 themselves into chains or ribbons. They, however, always remain within the vacuole though 

 the vacuolar membrane may not, in some instances, be readily distinguishable. — The spher- 

 omes are composed of ordinary microsomes isolated or associated in pairs or even chains. 

 They are never enclosed within a vacuole. — The cytoplasm of old cells is differentiated into 

 fibrils along which the microsomes migrate. These fibrils may, therefore, appear to be of 

 the nature of mitochrondria and have been referred to erroneously as chondrioconts. The 

 author is in favor of discarding the terms mitochondria, chondriosomes, chondrioconts, and 

 chondriomites, and substituting the terms vacuomes (metachromes and metachromatic 

 corpuscles), plastidomes (mitoplasts and plastids), spheromes (microsomes) and fibrils of 

 the cytoplasm, which he considers have more precise significance. — C. H. and W. K. Farr. 



984. Emberger, L. Evolution du chrondriome chez les cryptogames vasculaires. [The 

 development of chondriosomes in vascular cryptogams.] Compt. Rend. Acad. Sci. Paris 170: 

 282-284. 5 fig. 1920. — Two types of mitochondria are found in the root of Athyrium Filix- 

 femina, which differ slightly in the intensity of their staining reaction and in their size. One 

 gives rise to plastids, the function of the other is unknown. The author prefers to apply the 

 term mitochondria to the plastid-forming bodies as well as to those structures whose func- 

 tion is at present unknown. — C. H. and W. K. Farr. 



985. Emberger, L. Evolution du chrondriome dans la formation du sporange chez les 

 fougeres. [The history of the chondriosome during the formation of the sporangium of the 

 ferns.] Compt. Rend. Acad. Sci. Paris 170: 469-471. 7 fig. 1920.— In young sporangia of 



