468 Meyen's Report for 1839 on Physiological Botany. 



synthetica in statu primario seu primitivo, that is, when they 

 were still in the thallus in their natural position ; 2. asgonidia 

 synthetica in statu secundario, i. e. when they have risen above 

 the surface of the thallus and form soridia, the appearance of 

 which in the different genera is described. Finally, 3. the 

 gonidia are considered as reproductive organs. What Wall- 

 roth and Meyer have observed on this subject is correctly 

 stated to be not satisfactory ; and the author describes his own 

 experiments, which were made with great care in order to 

 observe the germination or development of the gonidia^ which 

 however were all unsuccessful. It is to be hoped that M. 

 Korber will continue his observations, for with the help of 

 our improved microscopes, there is doubtless much in this field 

 which remains to be discovered. 



Mr. Valentine* has communicated to the Linnaean Society 

 his obsei-vations on the development of the organs of fructifi- 

 cation of Mosses ; they contain, however, nothing that has not 

 been already made known. Mr. Valentine draws attention to 

 the analogy between the spores of Mosses and the pollen- 

 grains of higher plants. 



Dr. Stiebelf has written a treatise on the Oscillatoria which 

 is full of discoveries. According to his observations, the Os- 

 cillatorice are not only animals, but they possess also per- 

 fectly-formed heads ; they have a mouth, and when the Ly- 

 sogonium, which Dr. Stiebel has described and delineated, lies 

 on its back, it opens its mouth so that it assumes a triangular 

 form. Out of this mouth there comes a rostrum, which moves 

 rapidly in the water and creates a vortex ; it moreover pos- 

 sesses muscles, which spring from the lateral margin of the 

 animal. Generally at one end, or in young animals even at 

 both ends, are seen very peculiar tentacula or feelers which 

 execute a motion like that of oars ; they assume different forms 

 for the support of the rostrum and determinate purposes, and 

 exhibit a nerve. In the member which is connected with the 

 head-end is a kind of stomach with black hooks, which are 

 perhaps masticatory organs, and the bag of the stomach is 

 continued on like a rectum. The animal appears to live upon 

 small monads. Moreover the animal has at both ends pro- 

 jecting shining globules with black dots ; these are the eyes, 

 which can be turned round like snails' eyes, and have a nerve. 

 The Lysogonium did not appear to have two rostra, although 



* Annals of Nat. Hist. 1839, p. 456. Linn. Trans., vol. xviii. p. 499.' 

 "t" Uber den Bau und das Leben der griinen Oscillatorie Lysogonium 



tcBniodes Stieb. — Museum Senkenbergianum III. No. I. Frankfurt a M. 



1839, pp. 79—90. 



