\M) 



in i 



MARATTIALES 



rather strongly and lying neai the nucleus. The blepharoplast soon takes on the 

 curved form and becomes much extended and the cilia begin to develop from it 

 before the nucleus lias materially changed its shape. 



The nucleus now becomes slightlj pointed .it one end and begins to stretch 

 out so as to appear somewhat crescent-shaped, very much as in Ophtoglossum and 

 as it does in other ferns that have been described. With this change in the form of 

 the nucleus, the blepharoplast becomes still more elongated and strongly colored 

 and the cilia increase in length. The nucleus of the spermatozoid in Kaulfussia 

 is less elongated than is usual in the ferns, and in this respect, as well as in its larger 

 size, it more nearly resembles Ophtoglossum than it does the other Marattiacea?. 

 I he granular appearance of the nucleus is maintained until the spermatozoid is 

 almost fully developed, when there seems to he a fusion of the chromosomes so that 

 it appears almost homogeneous; this is accompanied by a noticeable diminution in 

 the size of the nucleus. The nucleus occupies only the large posterior coil of the 

 spermatozoid, while the anterior portion, which shows about two coils, is composed 

 of the blepharoplast with probably a certain amount of other cytoplasmic matter. 



Fig. 100. 



A. Cross-section of a ripe antheridium of D.jamaicensis. 



B. Cross-section of an empty antheridium; m, mantle cells. 

 C-D. Surface views, showing opercular cell. 



All figures X 350. 



In Marattia and Angiopteris (plate 2, tig. 4+) the nucleus of the spermatocyte 

 becomes much more extended and the whole spermatozoid is more slender than in 

 Kaulfussia. Indeed there is very little difference between the appearance of the 

 spermatozoids of Angiopteris and Marattia and those of the typical leptosporangiate 

 ferns. Some observations were made also upon Datura, in which the spermatozoid 

 is somewhat intermediate in character between that of Angiopteris and kaulfussia 

 (plate 2, figs. 42, 43). In size the spermatozoids are more like those of Angiopteris, 

 but the nucleus is much less elongated and the general form of the spermatozoids 

 is more like that of Kaulfussia. 



THE VRCHEGONIl M. 



The archegonium in the Marattiaceae, like the antheridium, very much resembles 



that of Ophtoglossum, but the neck of the archegonium is even less developed than 

 in the latter. Jonkmann ( Jonkmann I) has given a fairly complete account of the 

 development in Marattia and Angiopteris, and Farmer (Farmer 1) has described 

 and figured the archegonium of the latter genus. 



Usually, at least, the archegonium is developed only upon the cushion of tissue 

 back of the apex, the young archegonia arising in acropetal succession. Jonkmann 



