1 



) 



► 



1907] BURLINGAMESPORANGIUM OF OPHIOGLOSSALES 41 



in otner respects clearly abnormal, suttermg from external mjury to 

 the wall in one case, an abortion of the inner wall cells and neighbor- 

 ing sporogenous tissue in another, etc. In sporangia apparently 

 normal in all respects, a few of which were observed, no trace of such 

 a contribution was found. It is not unlikely, therefore, that this 

 genus agrees with the other two in this feature also, 



At the time the Plasmodium begins to penetrate among the crevices 

 of the sporogenous tissue they are rather small, and the movement is 

 therefore gradual. Hence the dcener narts of the crevices are emntv 



01 cytoplasm. By the time the sporangium has reached the stage 

 shown in fig. ^, the Plasmodium completely fills every crevice, showing 

 that the cytoplasm increases in volume after the breaking-down of 

 the walls. The nuclei do not at first penetrate among the blocks of 

 sporogenous tissue on account of the narrowness of the clefts, but later 

 as these enlarge they become distributed throughout the sporangium; 

 The structure of the plasmodial cytoplasm is at first coarser and 

 stains more deeply than did that of the tapetal cells before the 

 breaking-down of the walls. It has a ropy appearance and contains 

 many large granules. It does not seem to be definitely vacuolate, but 

 among the beaded threads there seems to be a fine hyaline sap-Hke 

 substance {Jig. 4). At this time the plasmodium docs not contain any 

 starch, which, however, soon appears and continues to increase until 

 the Plasmodium is fairly crowded with it (fig. 16). The stringy cyto- 



mes 



maximum 



vacuolate. The 



about the time the tetrads are complete. From this time on the 

 starch grains become fewer and fewer {fig. 25) until they have entirely 

 disappeared. By this time the cytoplasm, which has been growing 

 more and more vacuolate, has nearly all disappeared. The last traces 

 of it are to be seen along the old plasmatic membranes, which may 

 often be traced long after the more fluid parts have disappeared. 

 When the spores are of the age shown in figs. 26 and 27 all traces of 

 it are usually lost. 



The nuclei of the plasmodium exhibit frequent changes of form in 

 order to accommodate themselves to the spaces which they are com- 

 pelled to occupy, or into which they perhaps force themselves. WTiere 



one i«; fnnnri In o mT^^Trr^loff Tf Tioc fVic a nnpn ra n re of beinf? aboUt tO 



