42 WILLIAM PATTEN. 



dibles terminate in canals opening by a rather wide slit (fig. 

 12, d). (4) The gustatory cells always lie in bent canals 

 that gradually taper to a very fine opening (fig, 1). (5) 

 Finally, there is a set of canals like those of the gustatory 

 buds, except that they are capped by short spines of 

 varying shape and size, into which extends a chitinous tubule 

 (fig. 10). 



The sense buds of Liraulus have a certain resemblance to 

 the organs which in the Gephyreans have been described by 

 recent authors either as glands or sense organs. Organs 

 similar to those in Liraulus, but generally described as glands, 

 are widely distributed in Arthropods. 



The only thing resembling the gustatory cells in the mandi- 

 bular spines are certain organs in the extremities of the palps 

 and in the first pair of legs of Galeodes, as recently described 

 by P. Gaubert. They resemble the chitinous tubules seen in 

 Limulus, but histological details concerning them are so 

 meagre that it is impossible to identify them with certainty. 



I will also call attention to the " olfactory cones " of Mutilla, 

 as described by Franz Rulaud. They consist of spindle-shaped 

 clusters of cells from which a delicate hyaline tubule runs to 

 the perforated summit of the overlying cone. At the base of 

 the tube is a spindle-shaped swelling with longitudinal stria- 

 tions resembling those on the spindle of the gustatory cells of 

 Limulus. The organ also contains a single large nucleus that 

 may be compared with that in the sense buds of Limulus. 



The young stages of the sensory buds are much alike, 

 whatever the subsequent modification. They are probably 

 derived from the multiplication of a few ectodermic cells ; but 

 however that may be, the cells soon arrange themselves to 

 form a rounded body with a small central lumen (fig. 23). 

 The buds in this early stage stain more deeply in osmic acid, 

 and have a different appearance from that of the older buds 

 (fig. 22). The large ganglion-cell and the halo around the 

 central cavity are much more conspicuous at this time than 

 afterwards. Moreover the ends of the cells that converge 

 toward the central cavity are provided with refractive rod-like 



