NATURAL SCIENCES OF PHILADELPHIA. 401 



truncate anteriorly ; sides rounded, slightly margined, base truncate, angles of 

 thorax not prominent, the posterior rectangular. Elytra elongated oval, con- 

 vex, one-half broader at middle than the thorax, base scarcely emarginate, not 

 broader than the base of thorax, humeri prominent, deeply light striate, and, 

 with the marginal, deeply punctured ; interstices elevated, scutellar stria short, 

 distinct and punctured. Beneath smooth, very finely punctured. 



Long. -78 tf, -90 . Yucatan and Nicaragua. 



Very distinct from the species described from Cape St. Lucas by the charac- 

 ters above given. The thorax is evenly rounded, the posterior angles rectan- 

 gular, without being prominent as in gracilis Lee. The base is finely margined 

 by a line not reaching the angles ; in front of this a slight transverse elevation, 

 in front of which is an indistinct transverse impression. In the female these 

 characters are better marked than in the male. The antenna 1 are shorter and 

 much more robust; in the male they equal in length the head and thorax. The 

 front is deepty notched both in male and female, exposing the connecting 

 membrane between the epistome and labrum, exhibiting sexual characters 

 similar to Zophobas. The anterior tibia? of the male are clothed internally 

 near the tips with a dense, short pubescence. In this species the presternum 

 is slightly produced behind the coxae, acute. Mesosternum declivous and 

 broadly channeled. 



Between this genus and Zophobas there appear to exist close affinities. 



On the Consumption of Force by Plants in overcoming Gravitation. 



BY THOMAS MEEHAN. 



Every one interested in Horticulture knows how uncertain is the successful 

 cultivation of the grape in the United States. The vines usually flourish well 

 for a few years, but in most instances become the prey of numerous diseases 

 before they attain any very great age. 



In remarkable contrast with this general failure is the fact that grape vines 

 growing over trees are generally healthy and fruitful to a remarkable extent. 

 Branches from unhealthy vines on trellises, when they can get to ramble over 

 the twiggy branches of a neighboring tree, resume the health and vigor lost by 

 the parent or main vine. 



These facts have had numerous observers, and are generally admitted. They 

 have been frequently discussed in Horticultural journals ; but every theory 

 hitherto brought forward has been refuted. For instance, it has been sug- 

 gested that the partial shade afforded by the tree benefitted the grape vine ; but 

 it is as perfect when growing over low bushes, on hot banks, exposed to high 

 and dry temperatures, as when luxuriating among the shady branches of the 

 tallest trees. Again, it has been suggested that as the vine is supposed to like 

 a dry soil the roots of the tree tended to absorb superfluous moisture, and thus 

 furnished the best conditions for the vine roots ; but healthy vines are found on 

 trees in impassable swamps : besides, the cases of branches from trellises be- 

 fore alluded to answer this supposition. Some have thought that as the for- 

 eign vine, growing under glass, thrives there so well principally on account of 

 the humid atmosphere, the evaporation from the trees' foliage might benefit the 

 vine growing over it ; but it has been further observed that they grow as well 

 over dead trees as over living ones : and so on, in like manner, every theory 

 has been refuted, and the true reason unexplained. 



I think Mr. Darwin's discovery of tendril motion will afford the key to this 

 phenomenon, and enable us to form a new theory as to the origin and employ- 

 ment of force in vegetable growth. 



Mr. Darwin has shown that the tendrils of plants are in continuous motion 

 for a long time until they find something to cling to, when motion at once 



1866.] 26 



