396 SUMMARY OF CURRENT RESEARCHES RELATING TO 



BOTANY. 



GENERAL, 



Including the Anatomy and Physiology of Seed Plants. 



Cytology, 

 Including' Cell-contents. 



The Chondriome in Fungi and Algae.* — A. Guillermond has made 

 a long study of this body, which he considers of equal importance with 

 the nucleus in the life of the cell. He sums up his work thus :— 

 1. The presence of the chondriome has been demonstrated in so many 

 diverse forms that it appears to l)e universal. 2. In Algas it was 

 impossible to prove its presence in the Conjugatse or in the Conf ervace^e, 

 but it seems to be replaced by the chloroplast, which acts as a kind of 

 "reticulum mitochondrial." Other workers have found the chondriome 

 in the Florideaj and Phajophyce^. 3. There is evidently no chondriome 

 in the Cyanophycere. 4. As to the physiological function, they act in 

 fungi as do the leucoplasts in the higher plants, forming reserve 

 products as these latter form starch. Guillermond finds that the 

 metachromatic corpuscles take origin in the cytoplasm near the nucleus 

 and then migrate into the vacuoles. 



'»' 



Structure and Development. 

 Vegetative. 



Coniferous Wood of Potomac Formation, f — E, W. Sinnott and 

 H. H. Bartlett have studied numerous specimens of lignite and charcoal 

 from the Potomac formations and find that these represent two types of 

 conifers. The first type has wide tracheids with opposite pits, " bars of 

 Sanio," and a few large tracheids near the rays. The specimens appear 

 to be identical with GupressinoxyJon McGeei, but must now be regarded 

 as Podocarpoxylon McGeei, probably a species of Kageiojhsis having close 

 affinities with the Podocarpineae. 



The second type has narrow tracheids with small pits, no " bars of 

 Sanio," and a few pits near the rays ; wood-parenchyma is present, the 

 rays are shallow and thin-walled, "and there are well-developed resin- 

 canals. This type is classified as Faracupressinoxylon potomacense, 

 probably a species of Arthrofaxopsis, belonging to a group of small- 

 leaved mesozoic conifers having Araucarian affinities. 



* Rev. Gen. Bot., xxvii. (1915) pp. 193-207, 236-53, 271-88, 297-315 (12 pis.). 

 t Amer. Journ. Sei., sli. (1916) pp. 276-93 (18 figs.). 



