OP ARTS AND SCIENCES. 59 



and often 115 yu, long. The diameter of the trichogyne is much 

 greater, however, by reason of a very thick apparently gelatinous 

 sheath of high refrangibility. The whole trichogyne, including sheuth, 

 measures 5-6 fx broad. At the apex the sheath becomes much thin- 

 ner, and consequently does not materially increase the length of the 

 trichogyne. The cell of the trichogyne is often irregular in diameter, 

 frequently exhibiting considerable swellings, which however are not 

 followed by similar swellings in the sheath (Fig. 19). At the base the 

 cell broadens out where it joins the trichophoric apparatus (Figs. 18, 

 19). The trichogyne usually pierces the cellulose covering without 

 bending or other distortion, and extends for a considerable distance be- 

 yond the frond. Not infrequently, however, the trichogynes instead 

 of immediately making their way through the sheath, become bent 

 when they come in contact with its lower surface. They often grow 

 for considerable time between the outer layer of terminal cells and the 

 under surface of the cellulose covering before they succeed in breaking 

 through it. Below the trichogyne are three trichophoric cells. They 

 are usually somewhat wedge-shaped cells, of variable size. The order 

 of their formation I do not know. The one next to the trichogyne is 

 generally smaller than the others, and is set at somewhat of an angle 

 to them (a, Figs. 18, 19). In other words, the axis of the procarp 

 curves here. The other two cells of the trichophore lie side by side, 

 and are usually of about the same size (a', a", Figs. 18, 19). The tri- 

 chophoric cells are of a decided brownish color, and their contents are 

 quite clear. The cell b (Figs. 18, 19), on which the lowest of the tri- 

 chophoric cells rest, presents very much the appearance of the cells of 

 the rest of the frond. The cells c (Fig. 18, 19, 21) I take to be un- 

 developed terminal cells, previously referred to in the development of 

 the trichogyne. The cell b, and apparently in some cases a number of 

 the cells beneath it, are probably the carpogenic cells of the procarp. 

 In all the cases seen it did not seem that the trichophore played any 

 part in the formation of the cystocarp. In Figure 20 the cells a, a', a", 

 probably correspond to the trichophoric cells indicated by the same 

 letters in the other figures. If this is the case, the fate of the tricho- 

 phoric cells can be accounted for. After fertilization they shrivel up 

 and finally disappear, without developing further. In the same fig- 

 ure tr indicates probable remnants of the trichogyne, while the cells 

 b', h" , and h'" also are the outcome of the division of the original 

 carpogenic cell b (Figs. 18, 19). Some cases were observed where the 

 growth of the cystocarp seemed to originate even farther down in the 

 tissue of the plant, but nothing definite was established concerning 



