202 Bibliographical Notices. 



These tracts are at present inhabited by the following tribes : — 

 1. Warrans, along the coast, from Pomeroon to the Amacura; 2. 

 Arawaaks, intermixed with the former, chiefly at the rivers Waini, 

 Barima, and Amacura ; 3. Waikas and Chaymas, sister tribes of the 

 Wacawais, at the upper course of tliese rivers, and the regions be- 

 tween the Barama and Cuyuni. I estimate the whole number of 

 these nations at 2500. Many of them assist in felling timber or in 

 working on the estates ; and if the system which only of late years 

 has been followed, namely, that of treating the Indian as a rational 

 being, in giving him a fair remuneration for his work, shall be ge- 

 nerally adopted, the aborigines, there is no doubt, will prove most 

 useful labourers to the colony. It is my full persuasion, that if the 

 attention and paternal provisions which the aborigines of Guiana 

 have of late years enjoyed at theliands of Her Majesty's Government 

 be continued, and means adopted to afford them religious instruction, 

 a relic of the once numerous Indian population may yet be rescued. 



BIBLIOGRAPHICAL NOTICES. 



Die Pflanze im Momente der Thierwerdung . Beobachtet von Dr. F. 

 Unger. Wien, 1843, pp. 100, with a large quarto plate. 



The observations which Dr. Unger made many years since on the 

 peculiar motion of the spores of Vaucheria clavata, though questioned 

 by many, have for the most part been received as correct and well- 

 founded. Indeed they have been confirmed more or less by Trevi- 

 ranus, Meyen, Trentepohl, Valentin and others, and the fact is un- 

 doubtedly one of the most curious amongst those which have been 

 recorded of apparently spontaneous motion amongst the reproductive 

 organs of Algse. No one seems hitherto to have ascertained how 

 this motion is produced, with the exception of Dr. Unger, who in 

 the treatise before us has fully described the structure of the cuticle 

 of the spores, which it appears is clothed with short vibratory pro- 

 cesses, exactly as in many of the inferior animals, or particular organs 

 or membranes of those of a higher grade. The fact of the existence of 

 such processes in vegetables is not, however, perhaps altogether new 

 to science. Pouchet has described something of the kind in the larger 

 circulating globules in Zannichellia, thougli so imperfectly that the 

 real nature of the processes is not very evident. 



We now proceed to give the results of Unger's observations as de- 

 tailed by himself at the end of his treatise, which we think cannot 

 fail to interest our readers. 



1. Vaucheria clavata, Ag. {Ectosperma clavata, Vauch.) is, consi- 

 dered respectively of all its peculiarities, a plant, which by the union 

 of numerous individuals forms small tufts on the surface of stones 

 in running streams, in the middle of Europe. It consists, when fully 

 developed, of a branched inarticulate tube, 0037th of a Vienna inch 

 in diameter, which continues to grow above, while the lower portions 

 are dead or decomposed, and in this state lives from the end of winter 



