82 Chronicles of Science. [Jan., 
III. BOTANY AND VEGETABLE PHYSIOLOGY. 
Mr. Guuiver continues his researches among raphides, and brings 
out some curious results. In Vitacee he finds them universally 
present, while in Lindley’s Berberal alliance, the allied orders placed 
round Vitaceze are apparently universally devoid of them. Thus 
also Leea, placed by Lindley under Vitacese, contrary to the 
opinion of Von Martius and others, contains raphides like other 
Vitaceze, which order appears to be as truly a raphis-bearing one as 
Balsaminacee, Onagraceew, &c., are; and thus the importance of 
these minute organs becomes apparent. In a later contribution to 
the subject, he has continued his remarks, and finds that in every 
genus of Vitaceze examined there were traces of raphides, except in 
Bersama and Natalia, in which raphides are replaced by crystal 
prisms having four equal faces, their ends sloping off, either from 
angle to angle or from face to face. The same interchange occurs 
also in Roxburghiaces (Dictyogenee). The Araliceze abound in 
spheraphides but are destitute of raphides, while Pandanacee, like 
the rest of Lindley’s Aral alliance, abound in raphides. 
In the “ Comptes Rendus’ M. Boussingault describes some expe- 
riments upon the functions of the leaves of plants, the results of 
which appear to be:—I1st. That leaves exposed to the sunlight do. 
not decompose pure carbonic acid, or if they do, they do it with 
extreme slowness; 2nd. Under the same circumstances in a mixture 
of carbonic acid and atmospheric air they decompose the acid 
rapidly. The atmospheric air appears to have no active part in 
this phenomenon. 3rd. Leaves exposed to the sun rapidly decom- 
pose carbonic acid, when mixed either with nitrogen or with hydro- 
gen. Although the decomposition of the acid is a phenomenon of 
dissociation, M. Boussingault traces a pretty close analogy between 
it and the slow combustion of phosphorus. 
Mr. Roland Trimen gives in the ‘ Linnean Journal’ an account 
of the structure of Bonatea speciosa, a Cape orchid, from which it 
appears to be eminently adapted to insect fertilization, so that pro- 
bably the length of the nectary and the amount of nectar it contains 
are so contrived as to necessitate the hungry visitant’s probing 
even its head into the rostellum cup in order to obtain the sweet 
fluid, in which case the attachment of one or both of the viscid 
disks to some portion of the underside of the head or proboscis 
seems inevitable. The most remarkable point in the structure of 
this orchid is undoubtedly the erect process of the labellum. Its 
sole use and object are unmistakable, and its abrupt prominence 
seems 80 foreign to the general character of the labellum and petals, 
that it would be difficult to find, even in the orchidean order, a more 
striking instance of special modification. With the exception of 
