M. Tulasne's Researches in Vegetable Embryugeity . 345 



MM. Schacht and Deecke do not appear to have taken it into 

 account. 



Although amongst the gamopctalous plants with personate 

 corollas, great dissimilarities separate the Scrophularinere from 

 the Labiata', if we consider especially the structure of the fruit 

 and seed, yet the study of the ovule and of the generation of the 

 embryo reveals analogies between these two families which can- 

 not be mistaken. From the simplicity of its structure and the 

 softness of its tissues, the ovule of the Labiatfe, which has 

 hitherto been neglected by embryologists, is generally capable 

 of easy dissection. As in most of the Scrophularinea), the em- 

 bryo-sac presents vesicular inflations and appendages of very 

 various kinds both at its extremities and on the sides. The 

 anterior inflation, or that near the n)icropyle, usually projects 

 from the nucleus, and is sometimes suflBciently elongated even 

 to pass the apex of the ovule ; it is obovate and of middling 

 size in Lamium ; of the same form, but more developed, in the 

 Motherwort [Leonurus Cardiaca) ; almost globular in various 

 species of Stachys, Nepeta and Teucrium ; of immense size, sac- 

 like and often asymmetrical in Betonica, Acinus vulgaris, Pers., 

 Galeopsis and Dracocephalum. Towards the middle of this cer- 

 vical inflation is attached a tubular appendage, which is either 

 short and simple {Lamium, Stachys), or very long, branched and 

 sj)irally twisted [Betonica). The middle region of the embryonal 

 sac is also usually furnished with a short lateral appendage 

 [Lamium, Galeopsis, Stachys), or with a basal one, accompanied 

 by long divergent tubes {Dracocephalum peltatum, L.). This 

 same region alone is filled with the perispermic tissue, in the 

 midst of which the nascent embryo is buried. The latter is 

 always borne upon a long and very delicate suspensor, of the 

 same form as in the Scro))hularinere, which is attached to the 

 rounded apex of the sac ; but as the very considerable increase 

 of this embryoferous ampulla after fecundation often takes place 

 asymmetrically, and especially at the expense of its lateral ap- 

 pendage, so as to divide it into two very unequal lobes, the 

 suspensor may thus be seen fixed near the more or less deep 

 notch which separates the latter, and consequently removed 

 from the longitudinal axis of the ovule. The pollen-filaments 

 are slender, but appear to be nearly solid, from the dense and 

 very refractive matter with which they are filled. In order to 

 penetrate into the cavities of the ovary, after having descended 

 to the base of the style, they have to traverse the tissue of a por- 

 tion of the gynobase ; then meeting immediately with the funi- 

 culus of the upright ovule which exists in each compartment, 

 they rise in the parenchyma of the funiculus itself and only quit 

 it at the lc\el of the micropylc, — hence they can only be seen 



