216 CHAPTER OF VARIETIES. 



OAKS GROWN IN HYACINTH GLASSES. An occurrence has lately 

 taken ray attention, which is possibly not unworthy of notice, as illus- 

 trative of the eiforts made by natural productions to discharge their 

 functions in some other way, if interrupted in the ordinary way of 

 discharging them. The case was one of the rearing of an oak plant in 

 a hyacinth glass, according to the mode described in your first volume, 

 p. 177. The acorn having been suspended on a thread fastened round 

 it, as there described, in due time the germ burst the shell and made 

 its appearance at the smaller end ; but in thereupon proceeding down- 

 wards, the radicle was intercepted by the lower part of the shell, which 

 was not open enough to allow it to pass free. The radicle was accord- 

 ingly bent upwards ; when penetrating along the length of the acorn 

 horizontally, within the shell and of course within the thread which 

 surrounded the shell, it made its way out at the larger end; and 

 thence passed down at a right angle into the water, where it is now 

 luxuriating several inches deep, and with every prospect of the plumula 

 shortly shooting upwards, and becoming a tree in proper season. 



RURICOLA. 

 Holywood, Feb. 12/A, 1834. 



DR. KNOX ON THE STRUCTURE OF THE FOOT OP THE HORSE*. 



He demonstrated the navicular bone of the horse's foot not to be a sesa- 

 moid bone, nor a peculiar structure formed expressly for the horse, but 

 the Epiphysis of the Os pedis, or coffin-bone. This was proved satis- 

 factorily by a direct appeal to structure. Besides anticipating results 

 of practical consequence from this discovery, the author is led to ob- 

 serve, that an organ may be displaced and employed to perform different 

 functions in different animals, that the epiphyses of bones are intended 

 by nature to form separate bones in a vast variety of animals, and that 

 they may often lead to the discovery of the type of the skeleton in fossil 

 remains of extinct animals. 



DAILY FLIGHT OF ROOKS (C. frugilegus). It is a daily habit with 

 the rooks belonging to the rookeries situated several miles to the east- 

 ward of this town, from the end of one breeding season to the com- 

 mencement of the next, to fly to the west. I have often observed them 

 on Sennen Green, near the Land's End, at which place and in the neigh- 

 bouring fields they remain all day, seeking food, accompanied by jackdaws 



* Read before the Royal Society of Edinburgh. 



