57^ 
PHANEROGAMS. 
sporangia in Lycopodium. These explanations are so far confirmed by the occurrence 
of malformations, that the lateral axial and the marginal carpellary ovules are often 
enough transformed into foliar structures of ordinary fornr, while thjs appears never 
to occur with terminal or superficial ovules. 
These remarks have at present been confined to the ovule as a whole, although 
reference has already been made to the theory of Cramer on the various morpho- 
logical relationships of the nucellus and of the other parts, the funiculus and the 
integuments. Malformations^, which in this respect are even more instructive than 
the normal development, led Cramer to the conclusion that when the ovule appears 
to be the equivalent of a lateral branch or of the whole of a leaf, the funiculus and 
the integuments together correspond to the foliar structure in each case ; the nucellus 
arises from it as a lateral outgrowth, while the integuments correspond to the hood- 
shaped lamina of the leaf, growing over the nucellus. 
The ovules are sometimes rudimentary ; those of Balanophoreae and Santa- 
lacese have no integument ; the nucellus is naked, and in some species is itself 
composed of only a few cells. In Loranthacese the development does not even 
proceed so far as the formation of a distinctly differentiated ovule ; the growth of 
the apex of the floral axis ceases so soon as the carpels begin to be formed ; and the 
cohesion of these is such that it is scarcely possible to speak of a cavity of the ovary; 
the formation of the embryo-sac in the axial part of the tissue of the inferior ovary is 
the only indication that this spot corresponds to the ovule ; and since more than one 
embryo-sac is formed, it still remains doubtful whether this mass of tissue must be 
regarded as the equivalent of one or of several ovules^. 
The Develop7nent of the Ovule and of the Embryo-sac'^. [The first indication of 
the development of the ovule is the division by a wall parallel to the surface 
(periclinal) of one or more cells lying immediately beneath the epidermis of the 
placenta* ; in the case of ovules which have a simple structure when mature, as those 
* [See Masters, Vegetable Teratology, 1869; and Peyiitsch, Zur Teratologie der Ovula, Fest- 
schrift d. k. k. Zool.-Bot. Ges. Wien, 1876.] 
^ Hofmeister, Neue Beiträge, I (Abhandl. der kon. sächs. Gesellsch. der Wissensch. VI). [The 
remarkable position of the ovule in Hydnora {Prosopnnche) americana, immersed in the placental 
tissue, is comparable w^ith that of the sporangium in Isoetes (Fig. 334)- It is not possible to 
say at present if the embryo-sac of Hydtiora belongs, like that of the Loranthaceae, to an ovule 
which arises as a prominence on the placenta and is subsequently overgrown by it, or if it is 
developed from a cell of the placental tissue, the ovule not becoming differentiated from the placenta. 
On Hydtiora see De Bary, Abhandl. der naturf, Gesellsch. zu Halle, vol. X ; Hooker, Journ, Linn. 
Soc. vol. XIV. p. 182.] 
^ Hofmeister, Neue Beiträge zur Kenntniss der Embryobildung der Phanerogamen, Abhandl. d. 
sächs. Ges. d. Wiss, VI, VII, 1859, — [Strasburger, Die Coniferen und Gnetaceen, p. 409; id. Ueb. 
Befruchtung und Zelltheilung ; id. Ueb. Zellbildung und Zelltheilung, 3rd ed. ; id. Die Angiospermen 
und die Gymnospermen. — Warming, De l'ovule, Ann. d. Sei. Nat. 1878. — Vesque, Dev. du sac 
embryonnaire des Phanerogames, Ann. d. Sei. Nat. ser. 6, VI, 1878 ; id. Neue Untersuchungen, Bot. 
Zeitg. 1879. — Treub et Mellink, Notice sur le dev. du sac embryonnaire. Arch. Neerlandaises, XV. — 
Fischer, Zur Kenntniss der Embryosacentwickelung, Jenaisch. Zeitschr. XIV, 1880. — Marshall 
Ward, Embryo-sac of Gymnadenia conopsea, Quart. Journ. Micr. Sei. XX, 1880; id. Journ. Linn. 
Soc. XVII, 1880.] 
* [In the fourth German edition, Prof. Sachs, relying upon the observations of Hofmeister, 
regards the ovules of Orchideae as being trichomes, inasmuch as they are stated by Hofmeister to be 
developed from single epidermal cells of the placenta. Hofmeister's observations have been shov^n 
to be erroneous by Strasburger (Coniferen und Gnetaceen) and by Warming {loc. cit.). The ovules 
