OF THE EOTATORIA. 467 



Everghem, near Ghent, the Vauclieria clavata, in which I obseiTed something 

 similar. M. Unger had already published the following details respecting 

 this plant in 1828 : ' Beneath the emptied tubercles and at several points of 

 the principal stalk, at different angles, rather narrower branches are produced ; 

 these branches are generally very long, and greatly exceed the principal stalk 

 in length. At the end of ten or twelve days after their development, there 

 are seen, towards one or other of theii' extremities, here and there, at different 

 distances from the simimit, j)rotuberances of a clavate form, more or less 

 regular, straight or slightly bent back ; and others on the sides of the stalk, 

 which have the form of a capsule or vesicle. These vesicles are at first of a 

 uniform bright-green colour ; and without increase of size, which exceeds 

 several times that of the branches, they always become of a blacldsh-green 

 colour, darker tow^ards the base ; and then one or two globules of a reddish- 

 brown may be clearly distinguished there, often suiTounded by smaller gra- 

 nules, evidently destitute of motion, whilst the great ones move spontaneously 

 and slowly here and there in the interior of the capsule, by unequal contrac- 

 tions and dilatations, whence arise remarkable changes of form. I saw these 

 globules, at the end of eight or ten days after their appearance, still enclosed 

 in the capsule, moving more and more slowly, receiving no very decided in- 

 crease, whilst the base of the capsule became more transparent ; at last I 

 observed that, instead of their expulsion, which I was watching for, the 

 extremity of the capsule at the end of some days took an angular form, and 

 subsequently gave birth to two expansions in the form of horns ; it remained 

 in this state and became more and more pale, whilst the animalcule became 

 darker and died ; and afterwards it ended by perishing at the same time as 

 the other parts of the Conferva.' 



"Subsequent researches have not succeeded in informing us what this 

 animal might be, of which Unger spoke. As this author drew so much atten- 

 tion to the spontaneous movements of the propagula of the Vauclierice, and 

 as he admitted the passage from vegetable life — characterized, according to 

 him, by immobility — to animal life, the principal criterion of w^hich was 

 motion, his animalcule was confounded with the propagula ; and no one, so 

 far as I know, has returned to this very interesting subject. 



'' "VYhen, therefore, I found the Vauclieiia clavata at Everghem, I was as 

 much surprised as pleased to see the mobile body noticed by Unger better 

 than he did. With the aid of a higher magnifying power, I found it easy to 

 ascertain the true nature of the animal ; for it was not a propagulum, but 

 a real animal, the Rotifer vulgaris, with its cilia imitating the wheel, its 

 tail, (fee. 



" The first protuberances or vesicles which I saw containing this animal 

 enclosed but one of them ; afterwards they laid eggs and multiplied ; but it 

 seems that then they descend the tubes of the Vaucheria and lodge themselves 

 in new protuberances, whose development they may possibly stimulate, as the 

 gaUs and oak-apples, or organic transformations attributable to the influence 

 of parasitic beings. 



" The Rotifer vulgaris travels quite at his ease in these protuberances ; he 

 traverses the partitions, displaces the chromule and pushes it to the two ex- 

 tremities of the vesicle, so that this appears darker at these parts. One day 

 I opened a protuberance gently : I waited to see the Rotifer spring out and 

 enjoy the liberty so dear to all creatiu-es, even to infusorial animals ; but no 

 — he preferred to buiy himself in his prison, descending into the tubes of the 

 plant, and to nestle himself in the middle of a mass of green matter, rather 

 than swim about freely in the neighbourhood of his dwelling. 



'' Some of these protuberances had greenish threads appended to their free 



2h2 



