178 SUMMARY OF CURRENT RESEARCHES RELATING TO 



radiating threads. 3. During the prophase the chromatin passes along 

 the radiating threads to certain threads of the reticukim, which thicken 

 up ; and from these the spireme is organized. 4. The number of chromo- 

 somes is six ; and their number is not reduced during the last division. 

 5. During the reconstitution of the daughter-nuclei the chromosomes 

 show an end-to-end union, and a simple reticulum is formed by the de- 

 velopment of anastomosing threads. The chromatin gradually passes 

 from this reticulum and forms a nucleolus in the nucleus. 6. During 

 the anaphase of the last division a large particle of chromatin is gener- 

 ally detached from each of the daughter-chromosome groups and is 

 passed out into the cytoplasm. 7. Centrosome-like bodies occupy the 

 poles of the spindle during the last division, but not in the previous- 

 divisions. 8. The centrosome-Hke particle persists in the spermatid and 

 becomes the blepharoplast. 9. An extra division was observed in two 

 antheridia, and was preceded by the division of the blepharoplast ; but 

 the daughter particles did not in all cases occupy the spindle-poles. 

 10. The young spermatid contains, besides the nucleus, a conspicuous 

 blepharoplast. Most of the chromatin is passed from the nucleus into 

 the cytoplasm, and forms two spherical masses corresponding to the 

 single " Nebenkorper " of Ikeno. 11. An arched band is then developed, 

 probably out of the extruded chromatin, and passes round the periphery 

 of the spermatid, and joins the l)lepharoplast. 12. The nucleus lengthens 

 out along the arched band and re-absorbs most of it. 18. The nucleus 

 elongates further to form the body of the spermatozoid. At the an- 

 terior extremity is a small particle, probably the remains of the blepharo- 

 plast, and hereabouts the two long cilia are inserted. At the posterior 

 end is a conspicuous vesicle, the remains of the extruded chromatin. 

 14. In presence of water the ripe antheridium extrudes the spermatozoids 

 in a mucilaginous mass. Each spermatozoid rapidly revolves within a 

 spherical vesicle, from which in the laboratory it rarely succeeds in 

 escaping. 



Riccia.* — V. Schiffner gives an account of the structural peculiari- 

 ties of Riccia sorocarpa var. Hegii^ a new hepatic from Lower Austria 

 and Transylvania ; and, in a critical discussion, shows that it is system- 

 atically distinct from R. pseudopapillosa and R. papillosa. 



Weissia crispata.f — A. Cornet gives a careful description of the 

 characters of Weissia crispata Jur., a calcicolous moss hitherto unknown 

 in Belgium. It is related to W. viridula, and it ranges from Britain 

 to Tyrol and Marseilles. 



European Hepatics.f — K. Miiller publishes another instalment of 

 his monograph of hepatics in Rabenhorst's Kryptogamen-flora, treating 

 of the following genera : — NoiveUia (1 species), Pleuroclada (1), Hygro- 

 biella (1), Eremonotus (1), Cephaloziella (23). The genera and species 

 are minutely described and figured, and critical notes are added. The 

 genus Cephalozidla is distractingly difficult ; and the author had been 

 at great pains to make the matter as clear as possible by means of 



* Hedwigia, liii. (1912) pp. 36-40. 



t Bull. Soc. Roy. Bot. Belg.,xlix. (1912) pp. 18-19. 



X Leipzig : Kummer, 1913, pt. 2, Lief. 16, pp. 81-144 (figs. 24-40). 



