. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. IV. THE ANTHOCEROTES 143. centimetres or more in length, and reaches nearly this length before the first spores are ripe and the capsule opens. This it does by splitting at the top into two equal valves between which the dried-up columella protrudes. The split deepens as the younger spores ripen, and may finally extend nearly to the base. It is quite possible, although this point was not investi- gated, that the line of dehiscence corresponds to the primary verti- cal wall in the embryo, as is
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. IV. THE ANTHOCEROTES 143. centimetres or more in length, and reaches nearly this length before the first spores are ripe and the capsule opens. This it does by splitting at the top into two equal valves between which the dried-up columella protrudes. The split deepens as the younger spores ripen, and may finally extend nearly to the base. It is quite possible, although this point was not investi- gated, that the line of dehiscence corresponds to the primary verti- cal wall in the embryo, as is the case in the Jungermanniacese. The germination of the spores^ has hitherto been ob- served only in A. Iwvis. A study of the germination in A. fusi- formis shows a general corre- spondence with the results of other observers, but certain points were brought out that do not seem to have been observed in A. lavis. The spores of A. fusi- formis are protected by a per- fectly opaque black exospore, which is covered with small spines or tubercles. These spores will not germinate readily when fresh, but after resting for a few months grow freely. As in other similar spores, the ex- ospore is ruptured along the three ridges upon the ventral side (i. e., that with which it was in contact with the other spores of the tetrad), and through this cleft the endospore protrudes as a papilla which sometimes grows into a very long germ tube, or more commonly divides before it reaches a great length. Into this tube passes the single chromatophore which, during the early period of germination, has resumed its green colour, and with it the oil drops and other contents of the spore. A good deal of variation was observed here in the first divisions, as is the case in A. Icevis. The first division wall is, in most cases at least, transverse, and is usually followed by a second similar one, before any longitudinal walls appear. Then in the end cell two intersecting walls and the formation of four t
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