HARDWICKE'S SCIENCE-GOSSIP. 



8i 



I have a great variety of transverse and longitu- 

 dinal sections of Stigmarian rootlets, some just 

 emerging from the epiiierm, and others after leaving 

 the epiderm. In all these sections the outer of the 

 two layers forming the epiderm of the main root 

 is seen to be the one which forms the epiderm of 

 the rootlets. The inner and more prosenchymous 

 layer does not take any part in its formation. In 

 many rootlets the outer layer seems to be again 

 divided into two layers, having a dark line between 

 them. 



A true roo\\&i oi Slig)iiai-la ficoidcsco'Xi'i\%\.'s,, accord- 

 ing to Professor W. C. Williamson, of a vascular axis 

 of barred vessels surrounded by a layer of very deli- 

 cate parenchyma and an epidermal layer, the place 



REMARKS ON NORTH- AMERICAN PLANTS 

 Dog's-Bane. 



rHIS plant {Apocynuin androsiTinifoHiitn) is very 

 common here along the banks of the Maumee 

 River, generally growing best on the steep banks 

 where but few other plants can retain their hold ; but 

 it is not confined to these situations, as it grows in 

 borders of fields, and especially in cultivated ground. 

 It attains a height of from one to five feet, and is 

 much branched, this feature giving it the name of 

 "Spreading Dog's-bane." The leaves are ovate, entire, 

 and slightly petioled, opposite on the branches, which 

 are red on the side towards the sun. The flowers are 



Fig- 57- — Transverse section of Stigmaria (mag. 35 diam.), showing radial arrangement of the vessels of the ligneo'JS zone. 



a. Place of medullary pith ; d, -.voody or ligneous zone. 



between them being always destitute of tissue. But 

 there are many other rootlets which have this space 

 filled with tissue. The rootlets are not always found 

 round, but they occur in all shapes and sizes up to a 

 quarter of an inch and more in diameter. Their habit 

 of insinuating themselves into all sorts of places 

 caused them to modify their form according to cir- 

 cumstances. 



( To he con finned.) 



The White Ger.\nium {G. rohertiamnn) has 

 grown in a lane at Claverham, near Yatton, for many 

 years, and now seems to be extending its growth to 

 other parts. — JM. E. Winter. 



bell-shaped in a loose terminal cyme, somewhat 

 nodding, nearly white, tinged with purple. 



It commences to blossom in May, and blooms till 

 late in August, at which time the mature fruit and all 

 its intermediate stages can be seen. The fruit is a 

 pair of long slender follicles slightly united at the tip, 

 they contain numerous seeds. The whole plant 

 abounds in a milky juice, which exudes in abundance 

 wherever the plant is wounded. This juice is intensely 

 bitter, and I would infer from the author of " Cana- 

 dian Notes," p. 225, October Science-Gossip, that 

 it contained strychnia, but no authority I have at 

 hand speaks of this fact. The back of the root and 

 the whole root is used in medicine. In large doses it 

 acts as an emetic and cathartic, in small as a tonic- 



