12S 



I 111 MARATTIALES 



Hum and its general behavioi are so much like the form which occurs in Ophio- 

 glossum as to leave little room toi doubt that the two tonus are either identical 01 

 very closely related. The conidia (fig. 96, /), while occurring in the Marattiaceae, 

 are perhaps less frequent, but in form and structure are much like those of the 

 endophyte of Botrychium. I he most noticeable difference is the absence ol the 

 digestive cells, i. e., those that contain the varicose swollen mycelium. No evidences 

 were found in the Marattiaceae of the destruction ol the fungus by the cells of the 

 host and it is likely that the endophyte in these green prothallia is more nearly a 

 true parasite than is the east in the saprophytic gametophytes of the ( )phio- 

 glossaceae. In the infested cells of the green gametophyte the starch and chroma- 

 tophores are destroyed by the action ol the endophyte, but the nucleus <>t the cell 

 remains intact. 



I III SEXU \l ORGANS. 

 1 he w 1 111 uinn \i. 



I hi development ol the antheridium, except foi the details of spermatogenesis, 

 was correctly described In' Luerssen and fonkmann for Marattia and Angiopteris. 

 The other genera agree closely with these in the essential structure of the antherid- 

 ium. The development of the antheridium in the Marattiaceae agrees very closely 

 indeed with that of Ophioglossum. 



Fig. 97. — Development of the antheridium in Danaa. 



A. Section of prothallium, bearing antheridia on both surfaces. X8o. 



B-H. Longitudinal sections. X300. E-H, D.elliptica; the others, D. jamaicenyh. 



The mother cell of the antheridium, as in Ophioglossum, divides first by a 

 periclinal wall into an outer cell, the primary cover cell, and an inner one, from which 

 the mass of spermatocytes is developed (figs. 96, 97). The mother cell of the anther- 

 idium shows much the same variation in form as that of Ophioglossum, sometimes 

 being relatively broad and shallow and at other times deeper and narrower (fig. 96, 

 B, C). The first division in the inner cell is usually transverse, but in the broader 

 type of antheridium this first wall may he longitudinal. The primary wall is followed 

 by a second one at right angles to it and the four cells thus formed are again divided 

 so that there result eight nearly equal cells. The first wall occasionally is somewhat 

 oblique, but even in such cases the regular quadrant and octant walls arise at right 



