BOTANICAL SUBJECTS. 225 



Moreover, Dr. Masters (" Teratology ") mentions several cases, 

 in which sori are abnormally produced on the ventral aspect of 

 fronds, such as in Scolopendrium vulgare^ Polypodium anomalum., 

 Asjilenium, Trichomanes^ and Cionidium Moorei. 



It therefore would appear that the production of dorsal sori is 

 a question more of inheritance, convenience, and protection than 

 one of impossibility of ventral emergence. 



Apart from all this, is there really such a thing as ventral and 

 dorsal aspect of a leaf as something very different the one from the 

 other, from a morphological point of view ? They are simply the 

 two sides of a branch, which have for untold ages been turned the 

 one towards the light, and the other from it, thus acquiring by 

 heredity different functions. 



To show the utter insignificance of the position of the anther, 

 from a morphological jioint of view, it is enough to mention one 

 genus, that of Trillium. In some species of this savie genus the 

 anthers are introrse, in others marginal, and in others extrorse ! 

 It appears indifferent to this genus Avhere its anthers are placed. 

 To the species their position may be of importance. The right 

 position might mean easy powdering of some insects' hairs with 

 pollen for purjjoses of fertilization. The wrong position might 

 mean the reverse. One might imagine the genus Trillium^ 

 telling its species, " Place your anthers where you like, and fight 

 out your own battles. To me, their position is a matter of 

 indifference, but to you it may mean either prosperity or 

 extinction." 



It is a feature of so little importance that even a little twisting, 

 so common in many parts of plants, might change their dehiscence 

 from dorsal to ventral or vice versa. 



Warming, in his paper on the ovule (" Ann. des Sc.'Nat. Tom.," 

 5 and 6, Bot., 1878), finds that there is no essential difference 

 between the pollen cell and the nucellus cell of the ovu le. They 

 are both reproductive cells, and he compares the anther to a 

 sporangium, which Goebel says is a sac producing spores 

 endogenouslv. 



Goebel (" Outhnos of Classif .," p. 301) further says : " The 

 structure, origin, and the formation of pollen grains, by division of 

 the pollen mother cells into four parts, agrees in the minutest 

 particulars with the details given in the case of the sporangia of 

 the vascular cryptogams The important point 



A p. 1724. P 



