1907] BURLINGAME— SPORANGIUM OF OPHIOGLOSSALES 47 



not {figs. i4y i^y i8j 21) form before the next division. Probably this 

 depends on the rapidity with which the second division follows the 

 first, and perhaps the usual thing is for the second division to occur 

 when the daughter nuclei have reached about the stage shown in 

 iig. 14. At this time the chromosomes usually have not formed a 

 resting network, and the central part of the first spindle still persists. 

 If division occurs at this stage, the resulting figure usually resembles 

 figs. ly and 21. The majority of the spores are of the tetrahedrai 

 type. In this region of the cell, whether the wall forms or not, there 

 is always a noticeable collection of fine granular cytoplasm which is 

 sharply distinguishable from the less dense parts containing the 

 beaded strands already mentioned. Within this zone most or all of 

 the food granules are found; they are often so numerous and so 



r 



densely crowded as to make it difficult or impossible to tell whether 

 a wall is present or not. 



Early stages in the development of the spindle of the second divi- 

 sion were not observed. Metaphases are shown in fgs. 17 and 18, 

 and anaphases in jigs, ig and 20. All the spindles with the exception 

 of the type shown in jig. 18 are sharply bipolar, though somewhat 

 blunter than those of the first division. The spindle fibers are 

 markedly different from those of the first division; instead of a loose 

 bundle of very fine fibers, the fibers are heavy and coarsely beaded. 

 AH the spindles arranged as in jig. 18 have their apices truncated. 

 Fig. ig shows one spindle in the linear position, the other not; in 

 this type no truncated spindles were observed. Fig. 20 shows the 

 bilateral arrangement ; no other figure with this arrangement was ob- 

 served, though one case of bilateral spores was noted (jig. 25). Figs. 

 17-20 are arranged in the order of frequency of their occurrence in 

 the preparations. No spores were found which could be referred to 

 the types of division shown in f,gs. 18 and ig, which is singular, con- 

 sidering the frequency of this type of arrangement at time of division; 

 they were probably present, but were not recognized. In jig. 20 the 

 chromosomes seem to be passing into the network characteristic of 

 resting nuclei even before reaching the poles of the spindle, and long 

 before any nuclear membrane has formed. 



During maiosis the wall of the mother cell still persists and is very 

 noticeable, owing to its separation from the contents, for which it 



