ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 229 



how different they are in Orihezia catapTiracta from the same parts as 

 described by Mr. E. L. Mark for O, characias Bosc ( = 0. urticse L.). They 

 are followed by a description of the digestive tract. With regard to the 

 Malpighian vessels, the author commences at their point of insertion into 

 the mid-gut ; the common tube divides into two, and these two tubes again 

 divide into two branches which extend from the third to the eleventh 

 segment. Each pair forms a loop on either side, and the two unite in 

 the middle line ; all four vessels lie at first above the rectum. With regard 

 to their finer structure, it is noted that there is externally a transparent 

 homogeneous membrane in which no cell-nuclei can be detected ; in each 

 vessel there are two rows of cells, each of which in profile appears to be 

 six-sided. The cells are surrounded by a distinct membrane, and contain 

 bright spheres of various sizes; the nucleus appears after staining; it is 

 spheroidal or ellipsoidal, and has a distinct membrane with a nucleolus 

 which appears to the author to be an elongated thickening of the nuclear 

 membrane. Transverse sections through a vessel reveal the presence of a 

 central canal ; the vessels are very richly supplied with tracheae which are 

 mostly provided by the abdominal plexus. 



With regard to the manner in which the insect takes in its fluid food, 

 the author states that he was unable to convince himself of the presence of 

 any pumping apparatus, and he thinks that the fluid enters by capillary 

 action due to the canals of the bundles of setae. The arrangement and 

 histology of the salivary glands are described. 



The little-known nervous system of the Coccid^ reminds the author of 

 the great resemblance between its ventral medulla and that of the Myzo- 

 stomata ; in the supra-cesophageal ganglion he was able to observe unipolar 

 ganglion-cells, the largest of which were 17 /x long, and had a transverse 

 diameter of 11 ^u. ; two or three nuclei were to be seen in them, no distinct 

 membrane was to be detected, and no suggestions can be made as to their 

 function. The antenna are remarkable for the variations in the number 

 of their joints, and that even in one and the same individual, where the left 

 antennae may have eight, and the right seven joints ; another individual had 

 five or six joints. 



In an elaborate description of the generative apparatus it is pointed out 

 that from the yolk-spheres formed by the fusion of the epithelial cells there 

 is developed, after the degeneration of the nuclei of the epithelial cells, 

 a unicellular structure provided with a large nucleus — the mature yolk-cell. 



$. Myriopoda. 



Special Sensory Organs of Myriopods.* — Dr. E. Tomosvary describes 

 a peculiar sense-organ which he has observed in species of Lithohius ; it is 

 found in front of the eyes at the lateral margin of the head, where it has 

 the form of an infundibuliform depression, at the base of which there is a 

 small round orifice. The inner surface is clothed with ganglion-cells 

 connected with the optic nerve. In Polyxenus lagurus the organ lies on 

 either side of the head, and has three round orifices with projecting edges ; 

 in each of these there is a proportionately very long hair, connected at its 

 base with a ganglion ; the hair is movable in various directions. A very 

 different sense-organ is found in species of Pauropus at the ends of their 

 feelers between the tentacles ; this may be conical, or be surrounded by 

 two movable semilunar plates ; these organs are so small as to require 

 high magnification for their detection. Special sense-organs are also to be 

 detected in species of Glomeris ; in Scutigera they are at the base of the 



* Mathemat. u. Naturwiss. Berichte aus XJngarn, i. (1883) pp. 324-6. 



