PHYSIOLOGY AND MORPHOLOGY OF CALIFORNIA HEPATIC^ 3 1 



paraffin. The same method of fixation, deh3'dration, clearing 

 and infiltration were employed here as detailed in a previous 

 paper on the development of Fossombronia longiscta, barring 

 slifiht modifications. It was found that the best results could 

 be obtained by following the method of dehydration described 

 by Chamberlain.' The use of diffusion shells and the " con- 

 stant drip" process have proved somewhat unreliable, «ot 

 always giving satisfactory results for such tissues as prevail 

 among the more delicate hepaticge. Instead of transferring 

 from absolute alcohol directly to a 50 per cent, solution of 

 bergamot oil and then to pure bergamot, a more gradual trans- 

 fer was employed and a similar plan was followed in running up 

 through the paraffins. 



In the autumn of 1903 the writer revived some material con- 

 sisting of Fossombronia and Fiinbj'iaria and after a few hours 

 placed them in a fixing solution. On studying sections of each 

 it was observed that in the case of Fossombronia^ not only was 

 a considerable portion of the thallus alive but it was found that 

 there were nearly mature antheridia and archegonia. Sections 

 of Fimbriaria through the median sulcus proved the presence 

 of well-advanced antheridia. This suggested the possibility of 

 a similar early development of sex organs in other forms than 

 the two mentioned above. A number of slides of Riccia, Tar- 

 gionia, and Cryptoniitriiun as well as of Fossombronia and 

 Fimbriaria were prepared and in each instance, at least, anther- 

 idia have been found. Only in Fossombronia and Porella have 

 we found archegonia. In Fimbriaria and Cry^tomitriiim 

 these organs occur on special receptacles none of which showed 

 any sign of development. In Riccia and Crytomitriimi only 

 early stages of the antheridium were present which was rather 

 contrary to anticipation. A large number of plants of each 

 genus were sectioned and the great majority of them were 

 sterile. Qiiite early in the rainy season we have been in the 

 custom of collecting quantities of Riccia in which no difficulty 

 is experienced in obtaining virtually all stages in the develop- 

 ment of the sex organs. For this reason the writer feels that a 

 more exhaustive examination of this species ought to reveal 



'Chamberlain, 1905 : Methods in Plant Histology, p. 22. 



