MiTROPHANOW, Development of Nervous Elements. 165 



T. Ill, f. 33, 34,) the elements of the lateral sense organ are 

 more or less homogeneous, and Maurer insists on this ; in the 

 second, the difference between the central (sensory) and exter- 

 nal (investing) cells becomes manifest (1. c. T. I, f. 2, 5, 6). 

 Som.e cells, which form, according to my descriptions, the ner- 

 vous lateral sense organs, have an entirely different significance 

 from that attributed to them by Maurer ; his opinion contradicts 

 completely my conclusions as to the origin of the nervous lat- 

 eral sense organs of the Amphibians. I have already had oc- 

 sion to give my standpoint concerning the nature of the sensory 

 cells which KoUiker describes in the skin of the tadpole of the 

 frog. ^ 



The above mentioned investigations of Lenhossek do not 

 change essentially the doctrine of the peripheral nervous system. 

 His generalizations are not confirmed by his own later observa- 

 tions. In an article which appeared recently,^ he concludes 

 that the relations which he and Retzius have indicated in the 

 skin of the earth-worm, do not exist in vertebrates in any other 

 than the olfactory region. But even as to the last mentioned 

 point, one of the most accurate investigators concludes very re- 

 cently that the question of the connection of the olfactory cells 

 with the nerves must be considered as open, although many ob- 

 servers make out this connection, relying on the method of 

 Golgi.'" A very original explanation is given by Gorono- 

 witsch," for the processes which, until now, have been described 

 as the beginnings of the formation of the cranial nerves. 

 According to him, the outgrowths of the neural (ganglionic) 

 ridge do not have any relation to the development of the 

 nerves and ganglia, but simply take part in the development 

 of the mesoderm (mesenchym). His opinion is the same 



*P. MiTROPHANOW, Die Nervenendigungen und die Stiftchenzellen. 

 Zool. Anzeiger, 1886, 232. 



^M. V. Lenhossek. Der feinere Bau und die Nervenendigungen der 

 Geschmaksknospen. Anat. Anzeiger, 1893, No. 4. 



^''K. Arnstein. The End-apparatus of the Gustatory Organ. 1893. 

 1' N. Goronowitsch. Die Rolle der sog. " Ganglienleisten " im Auf- 

 V)aue der Nervenstamme. Anat. Anzeiger. 1892. No. 15. 



