1 62 Journal of Comparative Neurology. 



method, usually showing only silhouettes, is defective and very 

 apt to mislead in the matter of fibrillar connections. But in the 

 specimen in question viewed with a Leitz ocular No. 2, and ob- 

 jective No, 5, there is no more reason for doubting the contin- 

 uity of the lines shown than there is in fibrils shown in prepar- 

 ations stained with haematoxylin or any other histological color- 

 ing matter. They are not superimposed, nor is there any reason 

 for thinking them to be of tracheal nature. 



When we consider the nature of the method used, it should 

 hot appear strange that fibrils in very close contact should be so 

 impregnated with bichromate of silver as to cover up all evi- 

 dences of separation. In fact it seems to me that such apparent 

 evidences of continuity are to be expected, without, however, 

 even raising a doubt as to the complete validity of the evidence 

 obtained from the generality of terminations shown and from 

 histo-ontogeny. 



Before leaving the matter it must be noted that, although 

 the figure given is a camera drawing made with the aid of care- 

 ful focussing, it does not correspond with what appears when the 

 camera is removed. Then the fibres a, b and c are seen to belong 

 to the parallel fibres which are continued upwards beyond their 

 junction with the fibrillar branches of the incoming fiber. 



THE FUNCTION OF THE NERVE-CELLS OF THE MUSHROOM BODIES. 



Ever since Dujardin (50) discovered the mushroom bodies 

 and pointed out the relation between their size and the develop- 

 ment of insect intelligence, nearly every writer on the subject 

 of the hexapod brain who has referred to the matter of intelli- 

 gence has recognized the fact. Leydig ( 64) thought them con- 

 nected with the intelligence of the animal, but added that they 

 also seemed to bear some relation to sight, or to the ocelli. Rabl- 

 Riickhard (7.5) thought the same, except that he pointed out 

 that Leydig's second supposition is incorrect, since in blind ants 

 the bodies are found to be well developed, while the optic 

 lobes and the nerves of the ocelli are absent. Forel ( 74) 

 pointed out the same facts and added that the mushroom bodies 

 are much the largest in the worker ant, and that those in the 



