234 On Azolla and Salvinia. 



of the smaller sphaerical secondary capsules, the developments 

 are so much the same that they may be advantageously con- 

 sidered together. 



In both, the first steps consist in the development of the cells 

 of the superficies of the secondary capsules. (PL 18. f. 10. 

 11. 12. 13.) Shortly after, a cavity begins to appear in the se- 

 condary capsule, and this cavity then becomes filled with the 

 usual formative grumous matter (PL 18.,/. 17. 18. 20.) It 

 is in this grume that all the subsequent changes of impor- 

 tance take place. 



The first of these exhibits a variable number of irregular 

 granular nuclei (or coagula or condensations) in the grume, 

 which same coagula soon exhibit, (except in cases of abortion) 

 traces of being surrounded by a membrane (PL 18. f. 21. 

 23. 24.) 



A little later each secondary capsule will be found to pre- 

 sent a central mass of grume apparently connected with the 

 inner surface of the s. capsule by radiating grumous lines 

 (PL 18. /. 22.) the interstices of which are very generally 

 occupied at least partly by distinct cellular bodies with 

 one surface trifacial. On slightly pressing the secondary 

 capsules the grume escapes, and then presents, if attentively 

 examined, a few nuclei or coagula as before said, and a con- 

 siderable number of faintly defined cells, in most of which 

 traces are to be seen of ternary or quaternary division, and 

 as many nuclei ; also a few small trifacial cells, as above- 

 mentioned. 



The grumous mass of the secondary capsules resulting 

 from the larger papillae exhibits, however, in the centre 

 a cell containing granules, completely surrounded by grume 

 and apparently quite isolated (PL 19. /. 2.); with this ex- 

 ception and the difference in size, its contents may, I think, 

 be considered as identical with those of the others. But 

 this includes the curious difference of trifacial cells being 

 developed both in the centre and the circumference. 



