156 REVIEWS. 



mixed character of the foliage of Podocarpus, of which some 

 species have uninerved and others many-nerved leaves. The 

 numerous flower-buds along the periphery of the crown also 

 further favor this view." That is, in Welwitschia, where 

 this ingenious surmise carries a plausibility, which it does not 

 when api)lied to Podocarpus. 



The binary symmetry of Welwitschia, beginning with the 

 cotyledons, is carried through the inflorescence up to the de- 

 cussating pairs of bracts of the cones and the two leaflets in 

 each whorl of the hermaphrodite perianth. But the stamens 

 are six, at first sight a mouocotyledonous analogy ; yet they 

 may be regarded three sets of two, notwithstanding their 

 monadelphy. The flowers are dioecio-polygamous, i. e., of 

 two sorts, one female, the other structurally hermaphrodite, 

 but the gynaecium sterile, though well-developed, except that 

 no embryo-sac appears. The hermaphrodite cones and their 

 flowers accord in many respects strikingly with the male cones 

 of Ephedra ; but the anthers are trilocular, which is remark- 

 able. The simple ellipsoidal pollen is the same in both. In 

 Ephedra the stamens vary from two to eight, and the column 

 is solid, there being no rudiment of a gynaecium. 



The female fruitful cones are about three inches long, and 

 bright red when fresh. 



The integument of the ovule, as in Gnetum, is prolonged 

 at the summit into a style-like body, thus closely simulating 

 a pistil ; and the apex of this styliform tube, which is thin 

 and merely erose in the fertile flower, in the structurally 

 hermai)lnodite flower is dilated into a broad papillose disk, 

 exactly imitating a highly developed stigma — a marked in- 

 stance of a highly developed organ which is f unctionless ; for 

 no ])ollen has been detected u])on it, and no embryo-sac in 

 the nucleus. Here Dr. Hooker speculates upon " the pos- 

 sibility of Welwitschia being the only known representative 

 of an existing or extinct race of plants, in wliich such a 

 stigma-like organ was really capable of performing the func- 

 tion of a stigma. And, when we see this organ occurring in 

 a hennaplirodite flower, it is easy to suppose that we have in 

 Welwitschia a transition in function, as well as in structure, 



