364 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the inner side, and a vesicle, prolonged into a tube which, traversing 

 the neck of the gland, is attached to the root of the hair ; the vesicle 

 receives the secretion. Each gland is connected with a fine nerve- 

 twig. Seci'etion is probably voluntary. 



In Telepliorus this power is soon weakened and not rapidly 

 renewed. Among the adhesion-hairs are distributed others, supplied 

 by nervous twigs ; a ganglionic swelling is placed just below the end 

 of each of these. 



On the hairless globular tarsi of many Orthoptera almost all the 

 cells of the hypodermis of the sole form unicellular glands ; each sends 

 out a long fine chitinous tubule, which is connected with its fellows 

 by very fine hairs and is continuous with the chitinous coat of the foot 

 and opens through it. The sole of the foot is elastic and adapts itself 

 to minute inequalities of surfaces ; the interior of each tarsal joint is 

 almost entirely occupied by an enlargement of the trachea, which acts 

 on the elastic sole like an air-chamber, rendering it tense and at the 

 same time pliant. The apparatus found on the front legs of the male of 

 Stenobotlirus sihiricus must have the function of causing the legs to 

 adhere closely to the female by the excretion of an adhesive material ; 

 gland-cells and enlarged tracheae are found here also. Tlie hairs of the 

 anterior tarsi of male Carahi appear also to possess the adhesive 

 function. The adhesion of pollen to bees appears to be similarly 

 effected. The excretion is effected from the glands in Telephorus by 

 contraction of the protoplasm, which when the j)arts are teased in in- 

 different solutions exhibits active movements ; the secretion has been 

 seen to be driven from the internal vesicle into its neck ; many facts 

 as to vital contraction are given in support of this view of the cause of 

 the exudation of the glutinous matter. 



Salivary and Olfactory Organs of Bees.* — P. Schiemenz in this 

 elaborate paper commences with the ordinary bibliographical resume; 

 he describes in detail the structure of the parts of the digestive tract 

 which bears on the question of the salivary glands, and discusses their 

 developmental history and their function. He points out that all 

 glands have to sujiply a secretion, and that the more the separate cells 

 take a larger share in this, the richer the secretion from a smaller 

 number of secreting cells. In bees there are two essentially different 

 modes by which this is effected, and the two types may be approj)riately 

 spoken of as the intracellular, and the intercellular. In the simplest case 

 of the latter we find a sac lined by a simple layer of cells, so arranged 

 that each cell presents a proportionately broad surface to the common 

 cavity ; the material is obtained from the blood at the opposite ends 

 of the cells. If the sac elongates, its diameter diminishes and we get 

 the tubular form. In these two " systems " the cells are widest in a 

 direction parallel to the lumen of the sac or tube. If the cells 

 become sjjheroidal, there is a proj)ortionate diminution in the secreting 

 surface, and efferent canals appear between the cells. As a matter of 

 fact, glands of this kind of construction do, among the Ajjidse, stand 

 remarkably close to the saccular or the tubular. 



* Zeitschr. f. Wiss. Zool,, xxxviii. (1883) pp. 71-135 (3 pis.). 



