and Laboratory Methods. 1413 



Lawson, A. A. Origin of the Cones of the Investigations have shown that multi- 

 Multipolar Spindle in Gladiolus. Bot. Gaz. i • n r i 



30: 145-153, pi. 12, 1900. Po'ar spindles are of very general oc- 



currence in higher plants, at least in 

 the mother cells of spores. Since this type of spindle formation does not 

 require a centrosome, and since most investigators do not believe that centro- 

 somes are present, some other explanation must be sought for the ultimate bipo- 

 larity of the spindle. Those who have investigated the multipolar spindle 

 agree that it arises from a weft of kinoplasmic fibers, but they have not studied 

 the earliest stages. In 1898, the present writer in studying the pollen mother 

 cells of Cobea scandens found that the weft of kinoplasmic fibers arises from a 

 granular zone which he designated as the perikaryoplasm. In Gladiolus, as in 

 Cobca, there is a granular zone about the nucleus and it is probably from this 

 that the felted zone of fibers arises. The felted network about the nucleus 

 does not grow uniformly, but some portions grow more rapidly than others and 

 appear as projections which become the poles of the multipolar spindle. The 

 fibers of the spindle are formed by the elongating meshes of the network. The 

 nuclear membrane, the nucleolus and the linin take no part in spindle forma- 

 tion. The cones fuse into two groups to form the bipolar spindle. 



c. J. c. 



Longo, B. La mesogamia nella commune When Treub, in 1891, found that in 



Zucca (Cucurbita Pepo Lin.) Rendiconti Casuarina the pollen tube enters the 



della R. Accademia dei lincei. 10: i68- , , r i ■ i i 



172, I go I. embryo-sac by way of the chalaza, he 



gave the name chalazogamy to this 

 peculiar phenomenon and designated as porogams those plants in which the 

 pollen tube reaches the embryo-sac by the usual route of the micropyle. Chal- 

 azogamy has since been observed in several other members of the Amentiferce. 

 and in Uhniis a condition somewhat intermediate between chalazogamy and 

 porogamy has been described. According to Dr. Longo the pollen tube in 

 Cucurbita traverses the tissues of the funiculus and outer integument before 

 entering the micropyle. He proposes the name mcsogamy for this phenomenon. 



c. J. c. 



Bessey, Chas. E. The modern conception of Prof. Bessey accepts Miiller's view 



the structure and classification of Diatoms, , i ,-, i- • • i 



^vith a revision of the tribes and a rearrange- that the filamentous condition IS the 



ment of the North American genera. Trans. primitive one, and that diatoms should 



of the American Mic. Soc. 21: 61-8=;. pi. , , , • n <-, 



r igoo_ be regarded as typically filamentous 



rather than as unicellular forms. They 

 should then be classed between the Peridinialus on the one hand and the Des- 

 midiaceae and Zygnemaceae on the other. The Zygnemaceae are regarded as 

 the most primitive of the Conjugatae, while the Desmids and Diatoms are 

 believed to represent two similar and somewhat parallel genetic lines in which 

 the filaments tend to break up rather early into independent cells. The larger 

 part of the paper is occupied by a key to the tribes and genera of the American 

 forms. c. J. c. 



