210 REVIEWS. 



over within twenty hours to envelop them ; and when placed 

 on a medial line, a little below the ajiex, both margins incurve. 

 He concludes " that Pinguicula vulgaris, with its small roots, 

 is not only sup^jorted to a large extent by the extraordinary 

 number of insects which it habitually captures, but likewise 

 di*aws some nourishment from the pollen, leaves, and seeds of 

 other plants, which often adhere to its leaves. It is therefore 

 partly a vegetable as well as an animal feeder." The leaves 

 in one or two other species were found capable of greater and 

 more enduring inflection, and the glands excitable to increased 

 secretion even by bodies not yielding soluble nitrogenous 

 matter. 



The aquatic type of this family is Utricularia ; and the 

 bladder-bearing species of this genus are to Pinguicula nearly 

 what Aldrovanda is to Dionjea and Drosera — the bladders 

 imprisoning minute aquatic animals by a mechanism almost 

 as ingenious as that of Dionasa itself. Observations of the 

 same kind were made in this country by Mrs. Treat, of Vine- 

 land, New Jersey, before Mr. Darwin's investigations were 

 made known. These submerged aquatic stomachs, ever del- 

 uged with water, apparently do not really digest their cap- 

 tures, but merely absorb the products of their decay. 



The same must in all probability be said of such Pitcher- 

 plants as Sarracenia and Darlingtonia, which j\Ir. Darwin 

 merely alludes to at the close of his volume but does not treat 

 of. Nepenthes, however, according to Dr. Hooker's investi- 

 gations, has attained a higher dignity, and converted its })itcher 

 into a stomach. This parallelism, and this higher and lower 

 mode of appropriating organic products by each of the three 

 well-marked carnivorous families of plants, are highly sug- 

 gestive. 



In concluding this notice of a book for which we have no 

 room to do justice, — but which is sure to be in the hands of 

 many interested readers, — there is something to be said in 

 regard to the discovery of the lure in some of our San-aceuias. 

 We have by degrees to discover our discoverers. In this 

 Journal, only so far back as the number for August, 1873, is 

 a notice of the discovery of a sweet secretion at the orifice of 



