194 SUMMARY OF CURRENT RESEARCHES RELATING TO 



BOTANY. 



GENERAL, 

 Including the Anatomy and Physiology of Seed Plants. 



Cytology, 

 including Cell-Contents. 



On Fibrillar Structure of Protoplasm.* — G. Haberlandt confirms 

 Nemec's description of the fibrillar structure of protoplasmic strands in 

 liviug cells from the plerome layer of the root-tip of the onion, and also 

 in adventitious roots of Aspidium violascens. He points out that refer- 

 ence to such a structure has previously been made by various observers 

 of protoplasmic movement. His preparations as the result of fixing 

 and staining were also identical with those of Neinec. The suggestion 

 is made that the fibrillar structure is associated with the conduction of 

 plastic food-stuffs. 



Refringent Globules in the Parenchyma of Leaves.f — L. Petit 

 calls attention to the fi equent occurrence, in the chlorophyll parenchyma 

 of leaves, of strongly refringent globules (usually single), to which he 

 applies the term spherulin. As a rule their presence or absence is 

 characteristic of the greater number of genera in a family. They are 

 most frequent in the Garnopetalse with inferior or superior ovary, and 

 in the Polypetalae with inferior ovary. The author has failed to find 

 them in the Apetalse, or in the Polypetalae with superior ovary, except 

 in the Bosaceae. 



Structure and Development. 



Vegetative. 



On the Ksopo or Tanghin de Menabe (Menabea venenata Baill.), 

 a Poison Plant of the Sakalaves.J — E. Perrot gives an account of the 

 morphology and histology of this member of the Asclepiadaceae. The 

 latex contains a virulent poison, which resides principally in the root. 



Stem of Pteridophytes and Gymnosperms.§— Starting from the con- 

 ception that Van Tieghem's polystelic type of stem does not originate 

 by the repeated bifurcation of the epicotvledonary central cylinder, but 

 that the latter becomes at first a concentric fibrovascular tube, with gaps 

 for the branches alone, or with gaps for both leaves and branches, — 

 Dr. E. C. Jeffrey believes he has found, in the Osmundaceee, evidence 

 of the derivation of the medullated monostelic and astelic types from 

 the siphonostelic condition with internal phloem by the degeneration of 

 the latter. He is of opinion that there are two great primitive stocks 

 of vascular plants, — the Lycopsida and the Pteropsida. The former 



* Eer. Deutsch. Bot. Ges., xix. (1902) pp. 569-78 (1 pi.). 



t Comptes Rcndus, exxxiii. (1901) pp. 1250-2. 



% Op. cit., exxxiv. (1902) pp. 303-6. 



§ Proc. Roy. Soc, lxix. (1901) [.p. 119-20. 



