374 Dr. Lankester on the Origin of Wood. 



Since the greater part of these observations were made, the 

 third edition of Dr. Lindley's ' Introduction to Botany' has 

 appeared, in which I find he has noticed these formations 

 under the name of embryo-buds^, a name given to them by 

 Dutrochet. In his remarks, Dr. Lindley observes, that he can- 

 not reconcile the statements of Dutrochet, that they secrete an 

 independent cambium, and are "certainement" connected with 

 the wood of the tree. I have not seen Dutrochet's notice of 

 these bodies, but I can so far confirm his remarks, as to say, 

 that in most which I have examined there is a secretion inde- 

 pendent of the wood of the trunk, and that in others there is a 

 connexion, or rather a conjunction with the wood of the trunk. 

 This latter occurrence takes place occasionally where the buds 

 have been developed into branches, which is very seldom. 



The existence and growth of these bodies cannot be easily 

 explained on the theory of Du Petit Thouars, and Dr. Lind- 

 ley admits them to be one of the greatest objections. 



The only explanation that I can imagine the advocates of 

 this theory could offer, would be that the wood in the knobs 

 is formed by leaves which are occasionally developed, and 

 not every year with the leaves of the branches. To this I 

 would answer, that although I examined hundreds of these 

 knobs during the spring and summer of 1838, I never found 

 any leaves upon them; and it was only by a much more exten- 

 sive examination this year, that I found five or six knobs with 

 leaves upon them. 



The preceding observations have been made in the hope 

 that they might not prove uninteresting to those engaged in 

 botanical inquiries, and especially as the facts related have led 

 me to doubt the correctness of that theory which at one time 

 I considered as firmly estabhshed. 



Campsall, near Doncaster, Aug. 1839. 



Note. — Since the foregoing remarks were written some 

 valuable contributions to this department of inquiry by Dr. 

 Schleiden of Berlin have been published in the ' Annals of 

 Natural History,' and other publications in this country. His 

 paper on the Anatomico-Physiological Differences in the 

 Structure of Stems, in the December Number of this Journal, 



* From a further examination I think a more appropriate designation for 

 these bodies would be abortive blanches. 



