RECEPTACLES OF PKOPER JUICES. 109 



vesicles are sometimes slightly elongated, either when 

 they are found in parts where the cellular tissue is 

 elongated, or perhaps when two of the round cavities are 

 united. These oblong vesicular glands are very fre- 

 quently found in the leaves of the Samydeae : whatever 

 be their form, their juice never flows out unless the 

 envelope is broken. This effusion of the juice is very 

 visible in the leaves of Schinus molle : when cut into 

 fragments and placed into water, their juice escapes in 

 intennittent jets, which strike the water and cause the 

 leaf to recoil. The vesicular receptacles contain volatile 

 and aromatic oily juices. 



2d. Closed Receptacles (reservoirs en ccecum) are 

 kinds of short tubes, perfectl}' closed at one of their 

 extremities ; such are, for example, the little channels 

 full of volatile oil, which are obsen^ed upon the fruit of 

 Umbelliferffi, and which, commencing at the summit, 

 extend, in different species, to a third, half, or three 

 quarters of the length of the fruit. 



3d. Tubular Receptacles (reservoirs tubuleuxj, 

 described by Mirbel under the nam.e of Solitary 

 Proper Vessels (vaisseaux propres solitaires). These 

 are tubes of indefinite length, solitary in the midst of a 

 mass of cellular tissue. Grew has observed them very 

 well ; he has figured those of the Pine under the name 

 of Turpentine Vessels, and those of the Sumach under 

 that of Milk Vessels. Their walls are usually formed 

 of a very close and compact cellular tissue, as Mirbel 

 has seen in the tortuous reservoirs of Pinus strobus. 

 The interior of these is sometimes itself filled, at their 

 first development, with a cellular tissue, which is after- 

 wards destroyed. 



4th. Fasciculated Receptacles, or Fasciculated 

 PropeFv Vessels (reservoirs fasciculaires, ou vaisseaux 

 propres fasciculaires), discovered by Mirbel. These 



