2 24 LANGDON. [Vol. XI. 



work formed from the basal processes of these nerve-cells ; it 

 seems to me probable that much of this network is really a 

 part of the subepidermal network of the efferent fibres. Of 

 the nerve-cells themselves, he says, " Eine Gruppirung der- 

 selben zu dicht gedrangten Gruppen oder Organen, wie von 

 vornherein angenommen werden konnte, scheint nicht vor- 

 zukommen." In view of my interpretation of the facts, one 

 statement which Retzius makes concerning an appearance in 

 the cuticula is interesting. He describes, in cross-sections, an 

 appearance of fine lines crossing the cuticula perpendicularly 

 and then says, "an den Stellen wo die Sinnesnervenzellen die 

 Cuticula beriihren, sah ich ferner oft eine kleine hiigelartige 

 Erhohung der letzteren und ihre lineare Zeichnung verstarkt, 

 so dass das Ganze den Eindruck feiner Stiftchen (oder Kanal- 

 chen) machte, ohne dass ich die Natur dieser Bildung sicher 

 zu eruiren vermochte." From this description, I should judge 

 that Retzius saw, at least in some cases, the cuticular eleva- 

 tion over a sense-organ and the fine pores piercing it. In the 

 two illustrations which he gives of this appearance {I.e. PI. VI, 

 Fig. 2) the cuticula appears exactly like that over a sense- 

 organ but the cell beneath seems to me to be a very large 



gland-cell. 



Retzius found in the " Mundepithel " what he considered 

 might be " Geschmackszellen." These were apparently fibres 

 which passed through the epidermis and ended in an enlarged 

 part under the cuticula. His figures of these do not admit of 

 their being the sense-cells of the sense-organs. 



Netve-siipply of sense-organs. — Vejdovsky ('84) and Ude ('86) 

 both described a direct connection of nerve-fibres with the 

 sense-organs, but neither gave any evidence of this connection 

 or any evidence that the fibres were really nerve-fibres. Len- 

 hossek ('92) proved the direct connection of his nerve-cells with 

 nerve-fibres. If his nerve-cells are the sense-cells of the sense- 

 organs, he was the first to prove the connection of these 

 organs with nerve-fibres. His account of this connection and 

 his description of the course of these fibres has been with one 

 exception confirmed by my own work; I have never found a 

 sensory fibre crossing the circular muscles alone, but always 



