ON THE BRAIN OF THE COCKROACH. 349 



cannot be adoptedj as it is already in use for a region in 

 the human^-aia, and would certainly lead to much confu- 

 sion. L^ropose, therefore, to name this part the cauUculus 

 Uciai in figures). It will be convenient to call the hinder 

 branch given off from the trahecula (that is, the '' Hinterast " 

 of Flogel, and the "^ PilzsteiV of Dietl) the peduncle {p. in 

 figures) in allusion to its being the support of the so-called 

 mushroom body. It seems to me undesirable that this latter 

 name should be altogether abandoned, seeing that it has 

 been much used, and I propose, therefore, that each of 

 these structures, taken as a whole, be known as a corpus 

 fungiforme, while the inner trough-like portion of it, called 

 by Flogel the " Becher," will become the calix ; as there are 

 two of these on each side, they will be distinguished by the 

 prefix inner or outer [icx., ocx., in figures). And the 

 calicular cells may then be distinguished according to the 

 portion they occupy in the calix. The " CentralJmper'^ will 

 become the corpus centrale. I should prefer to retain the 

 name of antennary lohe for that part from which the 

 antennary nerve passes off, until we are more perfectly 

 acquainted with the functions of the antennce. 



It is proposed, in the first place, to describe in a general 

 way the series of sections, and afterwards to consider each 

 part separately. 



The first section consists very largely of the cortical cells 

 of the hemispheres, but includes a portion of one of the 

 antennary lobes, At the upper part on each side is tlie 

 rounded end of the cauUculus. In section No. 2 (fig, 5), 

 the cauUculus, which is strongly curved, occupies a large 

 portion of each hemisphere; it is sharply defined from the 

 surrounding parts, more especially from the mass of cells 

 arching over it above, which are coloured yellow by the osmic 

 acid. Fibres, arising from the middle line of the brain, are 

 seen passing outwards and crossing: the lower part of the 

 cauUculus. 



In section No. 3 the first traces of the calices of the 

 corpora fungiformia are seen as elongated patches above the 

 cauUculus, and within the cellular cap. In section No. 4 

 the calices have increased in size. In section No. 5 the 

 trahecula are seen for the first time, passing on each side 

 from the lower end of the cauUculus downwards to the 

 middle line. In section 6 (fig. 6) we have the first indica- 

 tion of the peduncle. 



In the following sections these processes increase in 

 size, while the caidiculi decrease ; the calices also increase 

 and become more and more deeply curved (fig. 7), until in 



