262 SUMMARY OF CURRENT RESEARCHES RELATING TO 



who is led by his investigations of the Sardinian specimens to give 

 an amended diagnosis of the species. Zigoselmis leucoa From. 

 According to the author's observations the different forms of develop- 

 ment of this species are found as spherical corpuscles of spori- 

 form aspect, different dimensions, and vivid rosy colour. These 

 are sometimes met with in immense quantities in saline waters ; and 

 so abundantly as to colour the water itself red, a well-known pheno- 

 menon at the salt springs. These sporiform corpuscles have a distinct 

 contour and a well-marked granular internal substance, some appearing 

 colourless. Two new species of Amoeba, A. d'ujitata and A. vclata ; o. 

 variety of Acineta Uuguifera C. & L. var. interrupta, and a new 

 form of A. Cattanei n. sp. Also Magosphcera Maggii n. sp., forming 

 a spherical group consisting of unicellular organisms or ciliated 

 spherules, distinctly nucleated and colourless, with flagolliform pro- 

 longations directed towards the centre of the sphere and cilia at the 

 opposite extremity pointing outwards. Prof. Parona considers that 

 this represents an organism morphologically antecedent to M. planula 

 Hack. 



BOTANY. 



A. GENERAL, including the Anatomy and Physiology 

 of the Phanerogamia. 



a. Anatomy.* 



Structure and Division of the Nucleus, f — In pursuance of his 

 previous researches J on this subject, L. Guignard has continued his 

 examination of the phenomena attending the division of the nucleus, 

 chiefly in the endosperm-cells and mother-cells of the pollen of 

 Endogens. Using aj)propriate reagents and a No. 12 homogeneous- 

 immersion objective of Verick, with condenser, he found, in the 

 nucleus of the mother-cells of the pollen in several Liliacea?, that the 

 thread is sometimes formed of two series of chromatic granulations, 

 even before its transverse segmentation. These granulations, placed 

 side by side, appear to result from the doubling of granulations 

 previously larger and placed in a single line. This doubling does 

 not extend to the hyaloplasm, and it is not usually visible until after 

 the transverse segmentation of the filament. 



One point in which the indirect division of the nucleus differs in 

 animals and in plants, is the occurrence of the am jihi aster in the 



* This subdivision contains (1) Cell-structure and Protoplasm (including the 

 Nucleus and Cell-division) ; (2) Other Cell-contents (including the Cell-sap and 

 Chlorophyll); Qi) Secretions; (4) Structure of Tiasues; and (5) Structuie of 

 Organs. 



t Bull. Soc. Bot. France, xxxi. (1884) pp. 324-30. 



1 See this Journal, iii. (1883) p. 864 ; iv. (1884) p. 915. 



