METHOD* 25 



than in that species. The best differentiation was secured by flaidea- 

 im-hacmatoxUiM 1 he blepharoplasu could not be made 

 t>ut prc ;irc pre*< 



A si-.- tnatogcnesU : :n>n was made to 



show that it is very much like th.r *hcr two species. Fig. 13. S. 



- the pair of spermatocytes with the Mrjarating membrane and the 



M< pharoplasts. The spcrmatocytes are somewhat larger than correspond- 



i /'. Zollingfrt. measuring alxnil 141 in length 



The Archegonium 



In all Buries of Pallavicinia the archcgonia are in groups sur- 

 as already M a double envelope : an outer one. ttte mvo- 

 mtich the more conspicuous before the fertilization of an archego- 

 niuin ; and an inner one, which is very small at first, but which after an 

 embryo is formed grows rapidly ami forms a conspicuous tubular sheath 



.eloping sporophyte. 



In /' / -shaped, with a lobed margin 



A ithui t 1 . -irnuin'ling the base of the archegonial 



group, is the ;>erianth. which at this stage does not reach above 



the level of th i the archeg /'. rodicuksa ( Fig. 13, 



A t B, E) differs from P. Zollingeri mainly in the much greater number of 



archegonia in the receptacle, and in the more flaring and deeply fringed 



P. Lr> omewhat intermediate in character, both as to 



the number of archegonia and the form of the involucre (Fig. 13, >). 



The receptacle is at first level with the surface of the thallus. but as 

 new archegonia develop it becomes raised and forms a more or less prom- 

 inent elevation, or placenta, to which the archegonia are attached (Fig. 



B). 



Of the three species examined, P. radiculosa was the best for the 

 study of the archegoniuir,. as all stages of development were present in 

 the material. P. Lcricri also showed most of the stages, but as it diffcrc I 

 from /'. rWuu.Wd an ex! is not made. None of 



the specimens of P. Zo\l\ ig archegonia, but to 



judge from the few immature archegonia that were seen it does not differ 

 essentially from the other spec 



Pollcrficinia radiculosa. while agreeing in the main with other ana- 

 crogynous Jungermanniales. in the development of the archegoniutn 



AS certain differences that may be noted. 



The youngest archegon 14. A, C) show a stalk composed of 



two or three cells, and a terminal, approximately hemispherical cell from 



