Prof. Morren on Infusoria in Plants. 345 



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 blackish-green colour, darker towards the base, 

 and then one or two globules of a reddish-brown may be 

 clearly distinguished there, often surrounded 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 contractions and dilatations, whence 

 arise remarkable changes of form. I saw these globules, at 

 the end of eight or ten days after their appearance, still in- 

 closed in the capsule, moving more and more slowly, recei- 

 ving no very decided increase, 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 after- 

 wards it ended by perishing at the same time as the other 

 parts of the conferva*." 



Subsequent researches have not succeeded in informing us 

 w r hat this animal might be of which Unger spoke. As this 

 author drew so much attention to the spontaneous move- 

 ments of the propagula of the Vaucheriae, and as he admitted 

 the passage from vegetable life, characterized, according to 

 him, by immobility, to animal life, the principal criterion of 

 which was motion, his animalcule was confounded with the 

 propagula, and no one, so far as I know, has returned to this 

 very interesting subject. 



When, therefore, I found the Vaucheria clavata at Everg- 

 hem, 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, &c. 



The first protuberances or vesicles which I saw containing 

 this animal, inclosed 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 protu- 

 berances, whose development they may possibly stimulate, as 

 the galls and oak-apples are organic transformations attribu- 

 table to the influence of parasitic beings. 



* Annales des Sciences Naturelles, aneienne serie, t. xiii. 1828, p. 438. 



