388 Prof. Meyen's Report of the Progress of 



I may also mention that Link*, Ungerf, and Morren J 

 have of late remarked that these doubtful creatures which are 

 known under the name of Bacillarice ought to be arranged 

 with vegetables ; according to this there would remain no other 

 botanist, with the exception of Corda, that had paid any con- 

 siderable attention to vegetable anatomy who did not con- 

 sider the Bacillarice to be plants. 



From this we may judge of the contradictions on this sub- 

 ject, which are found in the reports edited by Wiegmann 

 and myself on the progress of zoology and physiological bo- 

 tany for the year 1835§; as these creatures are at times men- 

 tioned as plants, at times as animals, and indeed under quite 

 different denominations ||. 



Morren, in the above-mentioned highly important memoir 

 on the Closteria? 9 has very fully treated the question whether 

 they should be arranged with animals or vegetables ; he suc- 

 ceeded, by employing very high magnifying powers, in show- 

 ing that those red and very moveable little points discovered 

 by Ehrenberg at the ends of these beings were nothing else 

 than minute vesicles which afterwards change into new indi- 

 viduals. It was these moveable and as it were oscillating 

 points which were considered as organs of motion, and ap- 

 peared to justify the placing of the Closterice among animals, 

 which however at present, after Morren's discovery, falls to 

 the ground. Besides the occurrence of these self-moving pi o- 

 pagula in the interior of the Closteria?, Morren has observed 

 a formation of fruit by conjugation quite similar to the mode 

 of formation of the fruit in the Cotijugatce% ; and besides this, 

 there also takes place an increase of the Closterice by separa- 

 tion. 



The siliceous envelope which surrounds the Closterice as well 

 as all other Bacillarice is regarded by Morren as a formation 

 analogous to the so-called cuticula of plants, a fact which is ca- 

 pable of confirmation only in certain relations; for in the per- 

 fect plants this fine plate of silica lies in the substance of the 



* Philos. Bot. Edit, alt., p. 400. 



f Vide his treatise on Algce in Endlicher's Genera Plantarum. 



X Sur les Closteries, I. c. § Wiegmann's Archiv. 



|| I am sorry to say that these contradictions must also occur in this year's 

 report; as I do not think Ehrenberg's view as to the animal nature of the 

 BacillaricE weakened by the reasons here stated. — Wiegmann. 



1 The same observation has been already made by Corda and noticed by 

 me in the report for the preceding year (1836, vol. ii. p. 186). It had al- 

 ready been mentioned by Ehrenberg also in 1834. (Beitr. z. Kenntn. gr. 

 Organis. in der Richtg. d. hi. Raumes, p. 95.) — Wiegmann. 



