76 Mr. GnirrrrH on the Development of 
tissues except in size. When the embryo is about half developed, the cotyle- 
donary division is deep, and the radicular end small; but as the development 
proceeds, the cotyledons, which were always rather unequal, become united, 
except at their immediate bases, corresponding to which sites two indistinct 
clefts may be found. At the same time the radicular end has become much 
enlarged*. Throughout its development the attachment of the embryo to 
the process is slight, and very easily ruptured. 
Finally, in the perfect fruit we find the viscous tissue occupying the whole 
space between the outer calycine layer and ovarium ; this is fibrous, somewhat 
indurated, obtusely 4- or 5-gonal, and prolonged upwards into as many points 
as there are angles. The albumen is colourless, fleshy, and of the same shape 
as the cavity of the ovarium ; the embryo is clavate, lodged in the apex of the 
albumen, beyond which and between its cornua the naked apex of the root 
may be seen to project T. 
The development in both the above genera is pretty nearly the same, if we 
except the want of the mammilliform process in Loranthus, and the unim- 
portant circumstance of the attachment of the embryo of Viscum being short. 
The following conclusions may therefore be applied to both. 
1. That the calycine parietes are from an early period intimately connected 
with the ovarium, and that the whole tissue between the outer calycine layer 
and ovarium becomes subsequently converted into viscum. 
2. That there is a tendency, varying in degree, in Loranthus in the ovarium 
itself to become softened down into viscum. 
3. That in Loranthus the ovarium is at an early period solid, as it is likewise 
in Viscum, if we look merely to the formation of the embryo. 
4. That the ovulum is formed subsequently to fecundation ; that its deve- 
lopment takes place in a cavity formed by the excavation of part of the tissue 
of the ovarium, | ! 
5. 'That the excavation commences as soon as the sphacelated line has reached 
the spot where the subsequent important changes are to be carried on. 
6. That the first development of the embryo takes place a considerable 
time after that of the ovulum; that it is attached to the apex of this by a 
cellular funiculus; that it is hence itself evascular. 
* Tab. XI. fig. 8 & 9. + Tab. XI. fig. 8. 
