6i6 MOSSES AND FERNS 



and Podomitrium (Campbell (34, 39) ) closely resemble Pallavicinia 

 Zollingeri in the arrangement of the antheridia ; but in Podomitrium 

 they occur on special ventral branches. In Makinoa the antheridia 

 are in chambers, very much as in Aneura. (Miyake (2).) 



P. 94. The archegonium of Fossombronia (Humphrey (i) ) some- 

 times regularly shows six neck canal cells. In Pallavicinia radiculosa 

 the writer found usually five or six, and in Calycularia radiculosa and 

 Podomitrium Malaccense the number is about the same, but may 

 probably in some cases be eight. Eight neck canal cells were also 

 found in Treuhia, although Griin states that he found sixteen in the 

 full-grown archegonium. (Griin (i), Campbell (40).) 



In Pallavicinia radiculosa the cap cell of the young archegonium 

 sometimes has several lateral segments cut off before the final quadrant 

 division occurs. There may be thus a limited apical growth of the 

 archegonium, somewhat as in the true Mosses, but such growth is 

 confined entirely to the outer cells. Podomitrium Malaccense may 

 show the same phenomenon. (See Gayet (i).) 



The archegonial receptacle in most Anacrogjmas, e.g., Pallavicinia, 

 Calycularia, Podomitrium, is surrounded by an involucre composed of 

 several usually laciniated scales. Sometimes, however, as in Sym- 

 phyogyna and Makinoa, the archegonial group is subtended by a 

 single scale. 



Within the involucre there may be developed a second envelope, 

 the perianth (see Fig. 41, A. per.), which forms a tubular sheath 

 often very conspicuous. The perianth does not form until after 

 fertilisation. It arises as a ring-shaped ridge about the group of 

 archegonia, and elongates rapidly with the growth of the young sporo- 

 phyte which it encloses. The perianth has evidently been developed 

 quite independently in a number of genera, while it is wanting in 

 others. 



P. 94. Aneura has been the subject of several embryological 

 investigations in later years. (Bower (22), Goebel (21), Clapp (i).) 

 Miss Clapp studied the earliest stages of the embryo and found they 

 agreed with Leitgeb's account. The very much enlarged basal cell 

 is a true haustorium. 



P. 95. The waU. of the capsule in Aneura is two-layered through- 

 out. 



P. 96. The apical mass of sterile tissue is known as an elaterophore. 



P. 96. The spore mother cells in Aneura become strongly four- 

 lobed before the nuclear division takes place. This is generally 

 characteristic of the Jungermanniales. 



