Structure & Development 0/Targionia hypophylla. 109 
III. Antheridial Receptacle. 
As is well known, the antheridia of Targionia are produced on 
short ventro-lateral branches, arising in the same way as the 
vegetative adventitious branches which in this genus almost entirely 
replace the dichotomous apical branching usual in most other 
Marchantiales. My observations on the structure of the male 
branches entirely confirm the account given by Kashyap (7) for T. 
hypophylla var. integerrima, and some additional details were made 
out. As stated by Kashyap and by Cavers, every transition may be 
found, in examining a large amount of material, between the typical 
short stalked discoid male branches and ordinary “ main ” shoots 
bearing antheridia. The explanation is simply that the male branch 
may either have its growth arrested after producing a discoid 
antheridial cushion or may continue its growth and thus give rise 
to a “main ” shoot which may branch apically or ventro-laterally 
or in both ways. Moreover, the growing apex in the former case 
may after a time cease to produce antheridia while continuing to 
grow, and in the latter case the branches formed may be sterile, 
in both cases leading to the formation of vegetative shoots. 
A careful examination was made of the arrangement of the 
ventral scales on the male shoots, as well as of sections taken in 
several planes through these shoots, and this confirmed Kashyap’s 
observation that the scales on these shoots are not arranged in two 
regular rows but are “scattered.” In some cases, however, a 
definite arrangement in radiating rows could be made out both in 
the insertion of the scales and in the position and age of the 
antheridia themselves ; that is, the youngest antheridia were found 
at several points on the periphery of the male “ disc ” or receptacle 
showing that the male receptacle of Targionia is essentially con¬ 
structed on the same plan as that of Marchantia, though its margin 
is not lobed. A closer comparison may be made with the male 
receptacle of Fegatella, which as shown by Cavers (4) represents a 
branch system in which repeated dichotomy of the apex occurs but 
each growing point has a very short period of activity, so that while 
a distinctly centrifugal arrangement can be discerned in the anther¬ 
idia the receptacle itself does not become lobed as in Marchantia 
where each growing-point continues to produce antheridia in 
acropetal succession for some time. These observations entirely 
confirm Kashyap’s view that the male receptacle of Targionia 
represents a condensed branch system, the non-commital term 
“condensed” being perhaps preferable to the term “ reduced ” 
