MacDougal: MORPHOLOGY OF hepatic elaters. 49 



In Cono'^.ephalus each receptacle or head contains a cluster of 

 from seven to nine sporogonia. These are conical in shape 

 and are filled with spores and radially arranged elaters. The 

 sporogonia of the material investigated at this time were mostly 

 in rather advanced stages of development, but a few younger 

 specimens were found. 



The method employed in working upon the material was as 

 follows: The entire contents of a single sporogonium were 

 mounted in water and with a low power an estimate was made 

 of the proportion of branched to unbranched elaters in the en- 

 tire mount. The most peculiar forms were then selected and 

 examined under higher power. Measurements were taken with 

 the micrometer and careful drawings made, giving special at- 

 tention to (1) the contents of the elater cell, (2) the thicken- 

 ing of the wall of the elaters, (3) abnormalities in branching. 

 Observations were made in this manner upon two or three 

 sporogonia in each head, and also upon several receptacles on 

 the same plant. 



The normal elater cell {PL IV. figs. 1, 2, 7) of Conocephalus is 

 comparatively short, thick and geniculate. It secretes on its 

 inner surface a thickened band of a brownish color which winds 

 spirally around the cell. This band generally branches shortly 

 after leaving the end of the elater. One or both of these 

 strands may branch a second time. In most cases the branches 

 fuse again at the opposite end, so that in general each end of 

 an elater is occupied by a single loop, while its middle portion 

 contains three, four or sometimes five strands running parallel 

 with each other. 



AccordiDg to citations already given, young elaters have been 

 observed to contain starch. But in all these instances the 

 writers assert that with the appearance of the spiral bands all 

 trace of the starch passes away. But in the youngest recep- 

 tacle examined, the spiral bands of the elaters {PL V. figs. 8, 9, 

 11), though only faintly colored, were clearly distinguishable 

 in outline, showing that they were quite well advanced in age. 

 These elaters were very abundantly furnished with starch- 

 grains. This circumstance may have been due to an overplus 

 of starch after the necessary amount had been used in the 

 building up of the thickened bands. It also suggests the orig- 

 inal nutritive function of the elater. In the elaters of the other 

 receptacles examined there was no visible trace of cell-contents 

 of any kind. In attempting to ascertain the character of the 

 secretion, the best result was obtained from treating with sul- 



