Vegetative Production of Flattened Protonema. 45 
though later it is of the normal monosiphonous thread type, the 
extremely reduced male plants and the leafy female plants arising 
as buds upon it in the usual way. In (Edipodium the germ-tube is 
a row of cells which is soon converted into a plate by flattening of 
the terminal portion, “ protonemal leaves ” of similar form arising 
from it as outgrowths of the basal cells of the plate itself or of the 
short monosiphonous portion below. In Diphyscium the protonema 
arises in the same way, but the protonemal leaves have a curious 
trumpet-like form. 
We now come to Tetraphis and Tetradontium, in which the 
germ-ltube gives rise, either immediately or after growing and 
branching for some time, to spatulate protonemal leaves which 
occur in tufts owing to new “leaves” arising by proliferation from 
the bases of the older ones. In Tetraphis , Correns has described 
as arising from the germinating spore erect protonemal shoots 
(“ Protonemabaumchen”) resembling those of Andrecea. These 
bore, however, instead of protonemal leaves, circular discoid gemma 
like those found in the characteristic gemma-cups of Tetraphis. 
Correns also describes and figures abnormal gemma, found in the 
axils of the outermost leaves of a gemma-cup; these are elongated 
and spatulate structures, presenting almost every possible transition 
between the filamentous paraphyses which occur among the gemma 
and sexual organs on one hand, and the gemma themselves and the 
protonema-leaves on the other. He also cultivated cut pieces of 
stem on moist sand and found that these gave rise to new plants, 
either directly or after first giving rise to a protonema leaf; in both 
cases the new growths proceeded from the outer cells of the stem 
and most often sprang from near a leaf, several sometimes arising 
from one leaf-axil. 
The interest of the observations to be recorded below lies in the 
discovery that in Tetraphis flattened or thalloid protonema, exactly 
like that arising from the spore, may arise from the stems of plants 
growing under natural conditions. What Correns observed in 
cultures has now been observed in nature, though the cases are 
perhaps somewhat analogous, since in the plants here described the 
apex had ceased to grow and had from some cause been injured so 
that it consisted of dead cells. 
II.— Observations on Tetraphis. 
The following curious method of vegetative reproduction was 
found occurring in a mass of Tetraphis pellucida growing on a 
