H. BOTANY AND HORTICULTURE. 371 



frequently fatty oil. The agency of light is requisite, the 

 yellow rays being chiefly efficient. Many plants require but 

 little light or but little warmth for assimilation. An in- 

 crease of temperature above blood-heat is injurious or 

 fatal, while an increase of light is only beneficial. The chief 

 absorption of carbonic acid for assimilation is effected by 

 the leaves, which give off oxygen in return. Another and 

 more constant vital activity of the plant is slow combustion, 

 with the giving off of carbonic acid ; and this is noticeable 

 only when the mass of assimilated carbonic acid sinks under 

 that which is given off, as happens at night. 



EESIN IN THE AGAEIC. 



It appears that the fungus known as the White Agaric 

 (Polyporus officinalis) contains nearly sixty per cent, of res- 

 in, and it is suggested that this mushroom may advanta- 

 geously be cultivated in large quantity on account of this 

 ingredient. 18 A, April 23, 150. 



OSTEUTHIN, A NEW VEGETABLE PEINCIPLE. 



A new crystalline vegetable principle has been detected in 

 the root of master-wort by Gorup-Besanez, to which he has 

 given the name Ostruthin. It crystallizes in white needles 

 or prisms, and contains no nitrogen. 21 A, Sept.^ 1874, 907. 



REVISION OF THE SUB-OEDER TULIPE^E. 



A revision of the sub-order Tulipeai, by J. G. Baker, has 

 recently appeared in the journal of the Linnaean Society of 

 interest to American botanists. This group of six genera and 

 one hundred and seventy-nine species is confined to the 

 north temperate zone, having its largest development in 

 Eastern Asia, but ranging largely on the one side to Europe 

 and on the other to California and the Rocky Mountains. 

 The tulip is the only genus not represented in America, the 

 lily extending across the continent, and the fritillary stop- 

 ping short at the Rocky Mountains. On the other hand, the 

 calochortus, numbering twenty species or more, is limited 

 to our more western territories. Of the half-dozen ery- 

 throniums, one is restricted to the Old World, the rest to 

 the New. It is singular that a species in the smallest genus 

 {Lloyclia serotina) should be the one most widely distrib- 



