Prof. H. Karsten on the Vegetable Cell. 409 



and of fresh leaf of P. crassipes, from Mr. Baxter : abundance of 

 raphis-cells, and of crystal prisms, especially in the pith. 



Xyridacea and Juncacea. — Bits of dried leaves of the three 

 following, from Mr. Baxter : — Xyris laxifolia and X. subulata : 

 no raphides. Philydrum lanuginosum (Xyridacese ?) : numerous 

 acicular crystals lying singly along the leaf, the margin of which 

 consists of prosenchyma, its transparent fusiform cells as long as 

 in many sorts of woody pleurenchyma. Raphides were not seen 

 in any of the few species examined of the British Juncacese. 



Palmacece. — Cocoa-mit ( Cocos nucifei-a), Ya\m-nu.t [Elais guu 

 neensis), Betel-nut {Areca Catecu), and Date-fruit {Phosniw), 

 from shops : no raphides. Of the following, portions of leaves 

 merely, when not otherwise noted, from Mr. Ward's fern-house, 

 and from Mr. Moore, Mr. Sowerby, and Mr. Baxter : — Rhapis 

 flahelliformis, R. Sierotzik, Elais guineensis, Latania borbonica, 

 Phoenix leonensis, P. dactylifera (root, stalk, and leaf), P. farini- 

 fera, P. sylvestris, P. humilis, Elate sylvestris, Seoforthia elegans, 

 Chameerops, two sp., C. humilis (bits of root and leaf), Corypha 

 australis, Areca alba and A. rubra : raphides either not present 

 or very scanty. A. crenata, Thrinax parviflora, Chamcedorea, sp., 

 and C. Scheediana : a few raphides. Areca sapida, Sabal um- 

 braculifera, Cer-oxylon Andicola, and Caryota urens : many bun- 

 dles of raphides. 



Pandanacece. — Leaves, from Mr. Moore and Mr. Sowerby, of 

 Pandanus utilis, P. spiralis, and Carludovica purpurata : a pro- 

 fusion of raphides, the bundles of which are much shorter than 

 their delicate translucent cells. Of this order. Prof. Balfour long 

 since observed, " their spermoderm has numerous raphides." 

 Edenbridge, April 7, 1864. 



[To be continued.] 



XL. — Histological Researches on the Formation, Development, and 

 Structure of the Vegetable Cell. By Prof. H. Karsten. 



[Continued from p. 290.] 



§ in. On the Polarity of the Joint-cells o/" Cladophora 

 glomerata. 



In an investigation of cell-development, Cladophora glomerata 

 cannot be passed over, as its course of development furnished 

 the foundation for the first theory of cell-formation, Mohl having 

 employed it in his important and suggestive researches upon this 

 subject — researches which have been repeated by all succeeding 

 vegetable anatomists, who, almost without exception, have con- 

 firmed the results obtained by that highly esteemed observer. 



Ann. ^ Mag. N, Hist, Ser.3. Fb/.xiii. 27 



