Fossombronia longiseta , A list. 
87 
of Fossombronia (F. tuberosa ), in which well-defined tubers commonly occur. 
This character is also shared by Geothallus luberosus , Campb., Anthoceros 
dichotomies , Raddi, Riccia cancellata , Taylor fide Stephan i, Riccia perennis, 
Stephani, Riccia bulbifera , Stephani, Anthoceros tuberosus, Taylor, Anthoceros 
phymatodes , M. A. Howe, Petalophyllum Preissii , Gottsche, Petalophyllum 
lamellatum , Hooker. Howe 1 was the first to call attention to the occur- 
rence of this fact in regard to Fossombronia longiseta , stating it to be 
especially true in specimens from Southern California. Whether the stem- 
thickening of plants grown in the extreme southern portion of the state is 
of the same character as that of plants farther north has not yet been 
determined, and whether the thickening is due to the disturbances set up 
by the fungus can be definitely ascertained only by cultures on sterilized 
soil. The fungus seems to be confined almost wholly to the stem and 
rhizoids, the latter sometimes undergoing modifications in the form of 
lateral swellings, some of which are strongly suggestive of short branches. 
In no instance have the sex-organs or sporogonium shown any evidence of 
infection such as is reported by Leitgeb 2 as occurring in the young 
sporogonium of Ptilidium ciliare ; by Garber 3 in Ricciocarpus natans ; and 
by Cavers 4 in Lophocolea bidentata , Cephalozia bicuspidata , Plagiochila 
asplenioides and Radnla complanata , and in the capsules of Pallavicinia 
Lyellii and Pallavicinia hibernica. 
Golenkin 5 (’02), described endotrophic mycorhiza existing in Mar - 
chantia palm at a, M. paleacea , Preissia commutata , Targionia hypophylla , 
Plagiochasma elongatum and Fegatella conica. According to this writer 
the fungal hyphae are confined entirely to the compact ventral tissue, and 
the infected cells never show the presence of starch or chlorophyll, though 
they still retain their nuclei and protoplasm. In Fossombronia longiseta 
infected cells may contain chlorophyll, and in some cells starch occurs, but 
in those cells that have reached an advanced stage of infection, neither 
starch nor chlorophyll could be made out. 
The occurrence of fungal hyphae in the rhizoids has been described 
by Janse 6 for Zoopsis and by Nemec 7 for Lophozia bicrenata , Lepidozia 
reptans and Kantia trichomanis. To these species Cavers 8 has added 
Cephalozia bicuspidata , Scapania nemorosa, Diplophyllum albicans, Plagio- 
chila asplenioides , Bazzania trilobata and Porella platyphylla . 
Methods. 
All material was fixed either in the field, where it was at once placed in 
the fixing fluid, or brought into the laboratory in large sods where it was 
placed under a bell-jar until time of fixation. Flemming’s weak solution 
1 Howe (’99), p. 80. 2 Leitgeb, Heft 2, Taf. iii, Fig. 26. 
4 Cavers (’03), p. 30. 5 Golenkin (’02), Bd. xc, p. 209. 
7 Nemec (’99), Bd. vii, p. 31 1. 
3 Garber (’04), PI. X, Fig. 40. 
6 Janse (’97), vol. xiv. 
8 loc. cit. (’03), p. 35, 
