234 EMBKYOLOGY OF VISCUM. [BOOK n- 



the thickness of a peppercorn. At a little later period, how- 

 ever, an ovule may be discovered; the easiest method of 

 effecting which is, to separate the central substance into two 

 parts, which is best done by gently drawing it to and fro. 

 The ovule forms a club-shaped excrescence, the cellular tissue 

 of which is arranged in concentric layers ; each cell contains 

 two phakocysts. On subsequently bringing the ovule, when 

 it has assumed the shape of a small, rather compressed sub- 

 stance, in contact with a drop of water, the water will 

 penetrate it and drive out the phakocyst with some force. 

 The application of a drop of tincture of iodine colours the 

 interior yellow, but leaves the granules uncoloured, which 

 only subsequently become coloured when iodine is applied. 

 Two thin club-shaped bodies are found next to the ovules at 

 this epoch, and some weeks earlier, three fibrous bodies, 

 rather thickened at the end. The author considers these 

 bodies as abortive ovules. The ovule, which is thin at the 

 lower end, might be compared with an embryo-sac, if the 

 position of the surrounding vascular system, and the com- 

 parison with the other parts of the fruit, did not contradict 

 it. The young embryo exhibits itself, as a small mass of cells, 

 at the point of the ovule, and nearly in contact with what 

 one might call the epidermis. The author never observed a 

 trace of a pollen-sac in the interior of the ovary, nor did he 

 ever discover the slightest indication of a special integument 

 for the ovule ; so that the latter exhibits nothing more than 

 a nucleus, as has been observed in the Santalacese, and even 

 in the Olacinese. This nucleus is attached by its base to the 

 bottom of the ovary, and has its point exactly in the opposite 

 direction, so that the ovule must be regarded as orthotropus. 

 The author never saw a cavity in the ovule of the miseltoe 

 when the embryo was forming, neither did he ever find an 

 embryo-sac. The embryo exhibits itself, first, as already 

 mentioned, at the upper end of the ovule or nucleus ; and the 

 embryo cell, or the young embryo itself, is subsequently seen 

 to be attached to a series of cylindrical cells in the cavity of 

 the ovule, which cells constitute a kind of umbilical cord, 

 but without a vascular system." 



These observations tend to throw doubt upon the necessity 



