404 M. Lestibouclois on the Vessels of the Latex, 



first accepted SchuhVs views, to abandon them more or less 

 completely. 



Thus Adrien de Jussieu entirely accepted M. Schultz's views 

 in the first edition of his ' Cours elementaire/ but in the fifth 

 edition of that work omitted the description of laticiferous ves- 

 sels, referring to the channels so called by Schultz as lacunae or 

 intercellular spaces which, as an effect of age, ultimately acquired 

 a special wall. He also no longer recognized cyclosis, nor the 

 nutritive nature of the coloured juices. M. A. Richard has like- 

 wise ceased to adopt Schultz's opinions, and, instead of recog- 

 nizing an analogy between the special juices of plants contained 

 in vessels and the blood of animals, concludes that those juices 

 are rather of an excrementitious nature, more akin to bile or 

 saliva, or fluids which are only indirectly concerned in nutrition. 

 " The proper juices are not," he writes (Elemens de Botanique, 

 yihme edition, p. 253), "the same with the descending sap." 



M. Lestiboudois would endeavour to dispel the obscurity and 

 doubt which thus prevail respecting the existence and nature 

 of latex and laticiferous vessels. He wishes to determine whether 

 plants have a special vascular system for the circulation of a fluid 

 analogous to the blood of animals, or, in other words, whether 

 there is such a generally diffused nutritive fluid, called latex, 

 distributed to all the organs of a plant by a system of vessels 

 termed laticiferous vessels. With this object in view, he pro- 

 poses to study the question first in the case of plants furnished 

 with coloured juices, which have more particularly been com- 

 pared by analogy with blood, and next in respect to plants with 

 limpid juices; and he advances the following propositions for 

 solution : — 



1. Are the coloured juices of plants analogous to blood? 



2. Are such juices distributed through the medium of vessels, 

 as in the vascular system of animals ? 



3. Are such juices gifted with the movement of cyclosis ? 



4. Are they met with in other reservoirs besides vessels ? 



5. Can the coloured juices in different reservoirs be distin- 

 guished from one another ? 



6. Are vessels of a similar character discoverable in the ge- 

 nerality of non-lactescent plants ? 



7. In non-lactescent plants are reservoirs found analogous to 

 the non-vascular reservoirs of coloured fluids ? 



8. Is there an organic apparatus in plants of a more general 

 character than that which encloses coloured juices, and which 

 may be considered to be intended to transport the nutritive 

 sap ? 



Beginning with the first question, respecting the analogy of the 

 coloured fluids of plants with blood, he remarks that such fluids 



