40 Mr Allan E. Grant on the 



Opalnia, Actinosphcarium, the Fi)raminifera, &c., and 

 records observations on a fungus {^Empusa micscarina), and 

 several Algee (three Cladopliora and one Vaucheria). 



He mentions that what have usually been considered 

 vacuoles in Empusa, are in reality nuclei. A great num- 

 ber of nuclei were also observed to be present in a fresh- 

 water Rhizopod. He finds it difficult to accept Ed. Van 

 Beneden's theory of " fragmentation," since he has seen all 

 the complicated changes usually taking place in the nucleus 

 during " indirect" division. 



M. Treub* has lately contributed a most important 

 series of observations on the occurrence of more than one 

 nucleus in the vegetative cells of phanerogams. He has 

 discovered that the multinucleate condition is constant in 

 the vegetative cells of certain plants belonging to the 

 Asclepiadacea\ Apocynacece, Uuj^horbiacece, and Urticacem. 

 This condition was -well seen in the bast fibres of Humidus 

 Lujmlus^ Urtica dioica, and Vinca minor, and in the latici- 

 ferous cells, proved to be simple and branched single cells 

 by De Bary of Ochrosia coccinea, Vinca minor, Cyrtosi- 

 pho/iia spectabilis, Plnmieria alba, Hoya, Gomphocarpiis 

 amjusfifolius, Stapelia ciJiata, and Melica dioica. 



Ed. van Beneden maintains that in cells with m(»re than 

 one nucleus, fragmentation is the only method of multipli- 

 cation of the nuclei. Treub, however, asserts that he has 

 traced in the bast fibres of Humulus Lupulus, Vinca minor, 

 and Urtica dioica, and in the laticiferous cells of Vinca 

 minor, and Urtica dioica, the division of the nuclei by the 

 ordinary method, with formation of nuclear plate, &c. He 

 .^ays that the nuclei in one cell generally divide simul- 

 taneously, but that he has seen thirty divide in turn in one 

 cell. Strasbiirger observed that the process of free cell 

 formation occurs in the same manner, but we have in 

 addition the aggregation of the protoplasm round the 

 nuclei, new cells being thus formed. Free-cell forma- 

 tion from one point of view may be looked upon as a 

 state of transition between the multinucleated condition 

 and ordinary cell division. Finally, these discoveries 

 tend to exalt the position of the nucleus, and lower that 

 of the protoplasm, 



i,. _ ^'l * ComjH&s Rni'iv.s, Ixxxix. (1879). p. 494. 



