64 * Analyses of Books. [July 



filaments of Protonema, which are generally converted into 

 Orthotrichum, Hypnum and other mosses. 



Kutzing has distinctly observed these threads of Proto- 

 nema formed by gl6bules of Protococcus. These globules 

 swell, being filled in the interior with a green liquid, and 

 are gradually expanded into filaments. It appears that the 

 formation of Alysphceria does not necessarily precede that 

 of the lichens, but that it is an independent structure. 

 Kutzing observed the Barhula muralis a moss, produced 

 from Protonema and also from a Protococcus. The genera 

 Zygnema and Mongeotia are generally found in shallow 

 water. When the water containing these plants is evapo- 

 rated, the Conferva quadrangula appears. From the Mon- 

 geotia genuflexa in this way proceeds the Riccia crystallina. 



From his observations Kutzing infers : — 



1. The formation of organic matter cannot take place, 

 except from elements of other organic principles already 

 dissolved. 



2. Simple globules ( Cryptococcus, Palmella and Proto- 

 coccus)^ may produce different plants according to the 

 influence of light, air and temperature. 



3. The superior algse are plants of very simple structure. 



4. The same superior structure may be produced from 

 original structures altogether different. Thus, the Barhula 

 muralis, is formed from the Protonema which comes from 

 a Protococcus, and again proceeds from the remains of the 

 dried Palmella hotryoides, without passing through the 

 stage of Protonema. 



Article IX. 



ANALYSES OF BOOKS. 



Introduction a Vetude de la Botanique ou Traite Eleinen- 

 taire de cette Science. Par Alphonse De Candolle, Pro- 

 fesseur a I'Academie de Geneve. Paris, 1835, 2 tomes.* 



This work in two volumes, accompanied with plates, contains under 

 a modest title a clear and methodical exposition of all the divisions 

 of which the extensive science of botany now consists, but formerly 

 limited to the more or less exact description of a smaller number of 

 plants. These divisions are Organography, or the description of 



• Bibliotlieque l^niverselle, January 1835. 



