On Azolla and Salmnia. 267 



EXPLANATION OF THE PLATES. 



AZOLLA PINNATA. 

 PI. XV. 



(Male Organs and Development and fecundation of the Female Organs,) 



(Ovula.) 



Fig. 1. Pair of organs (ovula,) with the involucrum somewhat 

 reflexed. 



2. Another pair rather more advanced ; involucrum re- 



moved. 



3. One of these magnified, about 400 times. 



4. Ovulum considerably more advanced, 250 times. 



5. A pair of the same more advanced : under slight 



pressure. 



6. Fully developed ovulum, in this instance no filaments 



were found connected with it, but grume is represented 

 projecting from the foramen. 



7. Fellow ovulum, burst accidentally ; about 300 times. 



The filaments passing out through the rupture were 

 noted to be apparently continuous with some of those 

 projecting from the foramen. 



8. Another ovulum, the filaments are seen plainly passing 



into the cavity, which was partly filled with their 

 disconnected joints, 300 times. 

 9. 9. Confervoid filaments ; undergoing certain changes while 

 attached to the axis, 550 times. 



10. Pair of fully developed ovula. 



11. Right hand one of the same pair, the space inside is 



filled with the disjointed component parts of the pro- 

 truding filaments. 



12. Pair of rather more developed ovula, the left hand one 



burst accidentally ; both seen under pressure. The 

 protuberances round the base of the nucleus distinct- 

 ly seen, also the paraphysiform bodies, the vascular 

 supplies of the ovula, and in the right hand one the 

 disposition of the component cells of the previously 

 continuous filaments. Both shew the first change 

 that occurs in the nucleus, and both would have been 

 calyptrate capsules ; 200 times. 



13. Another a little more advanced, burst and under pres- 



