ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 663 



production of the spindle, while part of it may, in some cases, be 

 extended into, and disappear in the cytoplasm. He contests the view 

 of Nemec that the nucleolus of the daughter-nuclei originates from the 

 spindle fibres. 



Reconstitution of the Nucleus and Formation of the Chromo- 

 somes.* — V. Gregoire and A. Wygaerts have investigated these questions 

 in the meristematic cells of Trillium, and in the second (homotypic) 

 division of the microspore-mother-cells of that plant. They believe 

 that the chromosomes produce the network of the resting nucleus by a 

 process of vacuolation or alveolisation. In the prophase of the next 

 division the phenomena are repeated in a reverse direction to that of the 

 telophase. It is very probable that the chromosomes which appear in 

 the prophase are identical with those that disappeared in the telophase, 

 having become in the meanwhile invisible, but without losing their 

 individuality. 



Formation of the Achromatic Figure in Pellia.f — V. Gregoire and 

 J. Berghs have investigated again the developing spores and also the 

 maturation division of the spores in P. epiphylla. Their observations 

 agree neither with those of Farmer, Davis, nor Chamberlain. They state 

 that the centrospores described in this plant have no claim to be definite 

 organs, for the whole achromatic figure is produced by a rearrangement 

 of the ordinary cytoplasmic reticulum. They point out that their 

 observations contradict several of the theories which have been put 

 forward to explain the mechanism of karyokinesis. 



Inorganic Phosphates in Plant Seeds and in Seedlings. $ — E. 

 Schulze and N. Castoro have tested the seeds of species of Lupin us, Lens, 

 Vicia, Zea, Picea and Pinus, for inorganic phosphates, and find these to 

 be absent except for a negligible quantity in the case of Plans. Strobus. 

 These results confirm those of Hart and Andrews. On the other hand, 

 etiolated seedlings of Lens esculenta, Vicia Faba, and Zea Mays, when 

 examined by the same method, were found to contain appreciable 

 amounts of inorganic phosphates. 



Structure and Development. 



Vegetative. 



Centripetal Wood in Leaves of Conifers. § — Ch. Bernard describes 

 the results of his examination of the histology of the vascular bundle- 

 system in the leaves of a large number of species of the genera of the 

 older tribes of Coniferas (TaxodieaB, Taxeas, Podocarpeae, Araucarieai) 

 from the point of view of the character and distribution of the trans- 

 fusion tissue. He regards this tissue as merely centripetal wood ; the 

 conifers are " diploxylees " in the same sense as the Cycads, but their 

 centripetal wood accentuates the reduction which is already manifest in 



* La Cellule, xxi. (1904) pp. 7-76, pi. 2. + Tom. cit., pp. 193-239, pi. 2. 

 % Zeit. Physiol. Chem. xli. (1904) pp. 477-84. See also Journ. Cliem. Soc, 

 lxxxvi. (1904) II. pp. 506-7. 



§ Beiheft. z. Bot. Centralbl., xvii. (1904) pp. 241-310 (1 pi. and 88 figs, in text). 



2 z 2 



