Insectivorous plants . ore interesting, as here the tentaclesare not directly excited, but receive an impulse froma distant point; nevertheless, they bend accuratelytowards this point. On the Nature of the Tissues through ivhich the MotorLrqmlse is Transmitted.—It will be necessary firstto describe briefly thecourse of the main fibro-vascular bundles. Theseare shown in the accom-panying sketch (fig. 11)of a small leaf. Littlevessels from the neigh-bouring bundles enterall the many tentacleswith which the surfaceis studded; but theseare not liere central trunk, whichruns up the
Insectivorous plants . ore interesting, as here the tentaclesare not directly excited, but receive an impulse froma distant point; nevertheless, they bend accuratelytowards this point. On the Nature of the Tissues through ivhich the MotorLrqmlse is Transmitted.—It will be necessary firstto describe briefly thecourse of the main fibro-vascular bundles. Theseare shown in the accom-panying sketch (fig. 11)of a small leaf. Littlevessels from the neigh-bouring bundles enterall the many tentacleswith which the surfaceis studded; but theseare not liere central trunk, whichruns up the footstalk,bifurcates near the centreof the leaf, each branchbifurcating again andagain according to thesize of the leaf. This central trunk sends off, low down on each side, adelicate branch, which may be called the sublateralbranch. There is also, on each side, a main lateralbranch or bundle, which bifurcates in the samemanner as the others. Bifurcation does not implythat any single vessel divides, but that a bundle. Fig. 11. (Drosera rotundi/olia.) Diagram showing the distribution of the vascular tissue in a small leaf. 248 DKOSEKA KOTUNDIFOLIA. Chap. X. divides into two. By looking to either side of theleaf, it will be seen that a branch from the greatcentral bifurcation inosculates with a branch from thelateral bundle, and that there is a smaller inoscu-lation between the two chief branches of the lateralbundle. The course of the vessels is very complexat the larger inosculation; and here vessels, retain-ing the same diameter, are often formed by theunion of the bluntly pointed ends of two vessels,but whether these points open into each other bytheir attached surfaces, I do not know. By meansof the two inosculations all the vessels on thesame side of the leaf are brought into some sort ofconnection. Near the circumference of the largerleaves the bifurcating branches also come into closeunion, and then separate again, forming a continuouszigzag line of vessels round the wh
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