196 PROCEEDINGS OF THE ACADEMY OF [1897. 



furnish illustrations. The English Oak, Quereus Robur especially, 

 will furnish scores of variations that have been selected from the 

 seed-beds of nurserymen, and given distinctive names. Many of 

 these differ from each other by characters quite as striking as those 

 which distinguish American Oaks from each other ; but we know 

 they are not hybrids because there was no other species with which 

 they could intercross, and they are not regarded as species because 

 of their derivation from Quereus Robur. This would not be a true 

 test of specific rank. It still savors of the old doctrine of the special 

 formation of species which we know is not true. With our modern 

 experiences we may expect occasional wanderings from a general 

 character as a result of an unusual expenditure of force. Usually 

 these displays of energy are not able to maintain themselves. Seed- 

 lings fall back to the habits of their ancestors. If, however, they 

 should be able to maintain themselves, they are entitled to rank as 

 species. They are species and nothing else. 



Seeing, as we must, that all this is so, and must be, why should 

 we refer to hybridity to account for individual changes, especially 

 as the warmest advocates of natural hybridity rarely get beyond 

 " supposition " in any case. 



ORIGIN AND NATURE OF GLANDS IN PLANTS. 



When treating of glands, authors point out their secretory and 

 excretory functions, and describe their structure and general char- 

 acteristics, concluding with the bare statement that "besides these 

 there are others which seem to have no office in the general economy 

 of the plant." It has always seemed to me that this class of gland- 

 ular bodies deserved closer investigation, and in 1869 I contributed 

 a paper to the meeting of the American Association for the Ad- 

 vancement of Science, at Salem, " On the Glands of Cassia and 

 Acacia,'"* indicating that in these and some other plants the 

 "glands" could not be otherwise than abortive branches. Though 

 the paper excited no discussion, it is fair to say the proposition did 

 not seem to meet the approval of the eminent botanists attending 

 that meeting ; but, so far as I know, no further attempt has been 

 made to investigate and explain the nature of these so-called glands. 

 It has always seemed to me a fair inference that if they are but ar- 

 rested or abortive branches, we might reasonably expect to find 

 occasional instances of an advance from their depauperized state. 



4 Proceedings of Am. Ass. Ad. Science, Vol. XVIII, p. 260. 



