731 



The variations of the hanen stem of this plant appear almost infi- 

 nite ; perhaps its normal character may be defined as nearly erect, 

 with spreading and slightly drooping branches : the following is an 

 enumeration of the more strongly marked varieties. 



A. — Stem erect ; branches simple, very rigid, erect and densely 

 crowded. 



B. — Stem erect; branches simple, less rigid, spreading, slightly 

 ascending. 



C. — Stem erect ; branches simple, gracefully drooping. 



D. — Stem erect ; branches compound in the same manner as in E. 

 sylvaticum, and gracefully pendulous. 



E. — Stem almost prostrate, with semi-erect, very long, compound, 

 feeble branches. 



F. — Stem prostrate, with scattered, simple, irregular, seraiprostrate 

 branches. Edward Newman. 



Art. CLXVIII. — Researches in Emhryogeny. By W. Wilson, Esq. 



(Continued from page 659). 



Having had opportunities, during a recent visit to North Wales, 

 for extending my observations on the embryo of Juniperus communis, 

 I now resume this subject, after a very careful examination, as one of 

 considerable importance in the present enquiry. On reference to my 

 former observations (Phytol. 625, fig. 3, 4), it will be seen that the 

 naked ovule consists at first of a wide-mouthed sac, at the bottom of 

 which is seated a roundish nucleus, somewhat flattened at the top. 

 The nucleus, at this early stage, is composed of a simple mass of cel- 

 lular tissue, without any tunic. The upper part of the ovules (of 

 which there are three in each flower) projects beyond the floral inte- 

 gument, and there is thus offered every facility for direct communica- 

 tion between the pollen and the nucule ; so much so, that the grains 

 of pollen might probably gain immediate access to the interior with- 

 out the intervention of pollen tubes. Indeed, if the views of Schlei- 

 den were well founded, and if the upper part of the ovule be denied 

 the function of a stigma, we might expect that this plant would clear- 

 ly and readily exhibit proof of such access. If we fail to trace the 

 pollen-tubes into the nucleus, where all the parts are so much exposed 

 to view, the integuments so few, and the whole structure so much sim- 

 plified, — in vain shall we hope to verify the statements of those who 

 maintain this doctrine ; and for this reason I strongly recommend 



