The Genus Phyllospadix 409 



In anthesisthe staminateretinacula, firm, chartaceous, over- 

 lapping laminae, lift, then recurve one by one, only as the in- 

 dividual anthers mature (Fig. D). They push off in this 

 process the spathe, and neither ever returns to the original 

 position, as their protective function of course ceases with the 

 discharge of the pollen. The cells of the outer epidermis of 

 an appendage at the line of flexure are longer and thinner 

 than the adjacent ones, and those of the inner epidermis are 

 shorter and thicker walled. Presumably an increase of cells 

 takes place among the latter at anthesis. 



The stigmas, only, of the j'oung pistils are extruded at ma- 

 turity (Fig. A). The spathe and retinacula closely invest 

 them, until by the growth of the fruit and the curvature of 

 the old spadix (Fig. E) the whole is carried out of the spathe. 

 But at no time is there a reflexing of the pistillate retinacula, 

 although Ruprecht's figures and some descriptive statements 

 assert the contrary. 



An interesting fact developed is the presence on the pis- 

 tillate spadix, alternating with the pistils, of pairs of rudi- 

 mentary anther lobes whose lower part is sufficiently de- 

 veloped to produce even a few pollens, the upper portion re- 

 maining an undeveloped cellulose point (Fig. G). No pollen 

 is apparently discharged, however. If these anthers had 

 been fully developed we should have precisely the arrange- 

 ment and appearance of the monoecious spadix of Zostera. 



In Zostera, apparently the older genus, there is a curved 

 ridge connecting the twin anther-lobes in their younger 

 stages. This is believed by Hofraeister and subsequent ob- 

 servers to be a "connective," and as each of the two lobes 

 has the two pollen-sacs or loculi of the ordinary anther-lobe, 

 ' the two lobes together form one quadrilocular anther, 

 which appears on the Zostera spadix alternating with the 

 single pistil. The rudimentary anthers on the pistillate 

 spadix of Phyllospadix are connected throughout their whole 

 existence with exactly such a curved ridge, shown in figure 

 G. On the staminate spadix, however, this connection is 

 scarcely traceable, even when the anther is very young, and 

 when it is mature the connective seems to have disappeared. 



