ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 265 



phenomenon was observed especially in the filaments in whicli the 

 antherozoids of Characeae are produced, the nuclei of as many as 

 thirty of these cells being often found in the same stage of division, 

 or with scarcely an appreciable diflference. In this object the strong 

 contraction of the nucleus could also be observed which precedes the 

 formation of the nuclear plate. The author compares the processes 

 of division of the nuclei of multinucleated cells with the simul- 

 taneous divisions, alternating with periods of rest, in cells arranged 

 in rows, layers, or groups. 



The author also figures the results of observations on the vegeta- 

 tive cells of Chara fragilis, for the purpose of determining whether 

 the septum owes its origin to a cellulose-ring springing from the 

 side-wall, as in Spirogyra, or whether, as in vascular plants, a plate 

 of cellulose is formed between the two yoimg nuclei, which continues 

 to grow at its margin until it finally touches the side-walls, or in 

 some other way. It was proved that the septum is formed precisely 

 as in vascular plants. Between the cell-filaments which together 

 constitute the barrel-shaped body, a cell-plate appears at a very early 

 period, never a parietal ring. In some cases, as in vascular plants, a 

 still imperfect cellulose-wall could be observed in the cell-plate, 

 which subsequently extended to the cell-wall. 



Cell-nucleus in the Secretion-receptacles and Parenchymatous 

 Cells of the Higher Monocotyledons.* — By the application of haema- 

 toxylin, F. Johow has examined the nucleus in the following descrip- 

 tions of cells : — The cells containing raphides of Tradescantia, several 

 Liliacese and AmaryllidacesB, Anihurium sagittatum, and Orchis macu- 

 lata ; the glandular cells of Anthurium sagittatum and Philodendron 

 cordifolium ; the laticiferous and resin-passages of Allium Cepa and 

 Aloe ; the tannin-passages of Acorus Calamus ; and the segmented 

 laticiferous V3ssels of Anthurium sagittatum. The nucleus was in 

 these cases always situated in the parietal layer of protoplasm. They 

 may be divided into three classes : the most normal are the tannin 

 and laticiferous vessels, where the nucleus has quite the normal 

 structure ; next, the laticiferous and resin-passages (Schlduche), 

 where the nucleus is enlarged ; while the greatest diversity from the 

 normal type is exhibited by the vessels containing crystals, where the 

 nucleus has undergone considerable change in form and structure, 

 and contains vacuoles. This is especially the case in Hyacinthus and 

 Tradescantia. In the vessels containing raphides of Tradescantia 

 virginica the nuclei vary greatly in form; they may be disk-shaped, 

 roundish, angular, elongated, rod-shaped, or sickle-shaped. 



The author is of opinion that the protoplasm and nucleus in these 

 vessels and passages are still in a living condition. 



Johow further asserts the presence of several nuclei in the 

 cells of the tissue of some Monocotyledons, and describes them 

 minutely in the case of Tradescantia, Allium Cepa, and Orchis macu- 



* Johow, F., 'Unters. uber den Zellkem in den Secretbehaltern u. Paren- 

 chymzellen der hoheren Monocotyledonen,' Bonn, 1880. See Bot. Ztg., xxxviii. 

 (1«80) p. 826. 



