293 NATURAL HISTORY OF PLANTS. 



instead of central, free or more less completely axile, with as many 

 ovules as there are cells or carpellary leaves. It is true the foliage 

 of the Mappiece, their aspect, and mode of inflorescence, are often those 

 of the Olacinece, but these characters, without much value here, are not 

 found in the Phytocreneoe, inseparable however from the Mappiece, by 

 the flower and fruit, and with their volubile climbing stems, alternate 

 or opposite leaves, often lobate, resembling outwardly much less still 

 the Olacinece, Santalece, or Loranthece, than the Terehinthacece them- 

 selves, recalling altogether by these characters the Menispermacece, 

 Sapindaceas, Ampelidece, etc. 



The Terehinthacece are woody and in general remarkable by the pre- 

 sence of a gummy resinous juice, often balsamic and sometimes caustic. 

 Their latex ducts, especially studied by Teectjl,^ are situated 

 both in the pith and bark, or in the latter only. Certain Pistachios 

 and Sumachs have at first only one proper duct in the woody body 

 of their root opposite the middle of each of the four to six fibro- 

 vascular bundles. Later, others .appear on two or three concentric 

 lines, then they are anastomosed, and may even form a very rich net- 

 work. According to the observer we have just named, ' ' in the trunk 

 of Rhus J Pistacia, Schinus, etc., the proper ducts of the bark are 

 never exterior to the liber. The first appear ^ in the cortical bundles 

 themselves, at very nearly the same time as the tracheae on the inside 

 of the bundle." The reservoirs of latex may show themselves in plants 

 destitute of membrane, and they show moreover very varied modifi- 

 cations in the different species observed. Often, at the time of the fall 

 of the leaf, the proper ducts of the base of the petiole are obstructed 

 by the multiplication of the cells forming the walls. Maechand ^ 

 has proved a great resemblance of organisation between the stems of the 

 Anacardieoe* and Bursereee. The latter ^ have the general structure of 

 Dicotyledons, and although the reservoirs of balsamic juice are found 



' In Compt. Seivi. Acad. Se.lxv. 17 ; in Adan- * On the trunks of these see also: Kieser 



sonia, viii. 121. Mem. Sur. VOrg. (1814), t. 16, 17.— C. H. 



2 Often under the form of slits not filled with Schultz, in Nov. Act. Nat. Cw.'xvii'i (1841)' 

 liquid and surrounded by large cells which Suppl. ii. t. 20.— Oi.iv. Stem, in Sicot. 11. 

 -frame them like a wall. s Adansonia, viii. 56, t. 2 3 



3 Anaoard. 152, t. 3. ' " 



