530 Prof. Meyen's Report of the Progress of 



pearance is quite similar, are to be considered as milk ves- 

 sels, cannot be right. I have not yet been able to succeed 

 in observing in Ficus elastica the closed ends of* the milk 

 vessels, neither could I see partitions in these vessels; but 

 I have seen real anastomoses, even in Chclidonium majus 

 and in many others. 



That the sap in the milk vessels moves had already been 

 previously confirmed by Link, and it has again been observed 

 by him ; and he most admirably remarks, that this motion is 

 neither effected by the contraction of the vessels, nor by the 

 motion of the molecules contained in the sap, since obser- 

 vation does not show it. 



From various travellers* who have remained for some time in 

 Columbia, several notices have appeared, from which it is pro- 

 bable that in the districts in question there occur many other 

 kinds of trees which produce a milk similar to that of the cele- 

 brated Cow-tree f, respecting which von Humboldt has in the 

 accounts of his Travels (chap. xvi. and xxvi.) given us such 

 highly interesting communications. 



Mornay has again diffused through the medium of the 

 journals very interesting notices on Euphorbia phosphor esc ens, 

 with the inflammable milk This shrub grows near St. Fran- 

 cisco in Alagoas in Brazil, in impenetrable thickets, covering, 

 perhaps, more than 1000 square feet. According to the 

 statement of the natives, it sets light to itself, throws out for 

 a long time an immense column of dense smoke, and finally 

 breaks out into bright flames %. 



On the Secretory Organs of Vegetables, 



L. Griesselich§ has with great propriety addressed some 

 admonitory hints to vegetable physiologists on the subject of 

 our defective knowledge relative to the structure and import- 

 ance of glands ; he also observes that even what De Candolle 

 has reported in his celebrated physiological works is unfor- 

 tunately not adapted for throwing any light on this subject. 

 He also cites various passages from those works which satis- 

 factorily prove this. Griesselich's statements respecting this 

 subject are, however, not founded, any more than De Can- 

 dolle's, upon personal observations with the compound micro- 

 scope ; if, therefore, there is nothing new in the memoir, yet 

 it has the merit of having directed attention to a subject so 



» Loudon's Gardener's Magazine, 1836. No. 71, p. 100. 



t [See Sir R. K. Porter's description of this remarkable tree in the present 

 volume of Phil. Mag., p. 452. — Edit.] 



\ [Mr. Mornay's first notice of this plant will be found in Phil. Mag., 

 First Series, vol. xlviii., p. 423. — Edit.] 



§ On the Glands on the Leaves of the Labiataz, and on the odoriferous 

 constituent parts occurring in them.— Botanical Papers, part i. Carlsruhe, 

 1836. 8vo. 



