ZOOLOGY. 445 



The Blood of Insects. 



The characteristics of the blood of insects have been investigated by 

 M. L. Fr6d6ricq, of Belgium, as manifested in the larva of Oryctes nasi- 

 cornis, a lamellicorn beetle. Blood drawn from the dorsal vessel by a 

 glass cannula was a colorless fluid having nearly the same appearance 

 as the lymph of mammals, but numerous colorless globules diffused 

 through the fluid negatived complete transparency. Coagulation super- 

 vened immediately, and the fluid turned to a dark-brown color soon after 

 exposure. This change was due to oxidation, and not at all to light. 

 The coloration is not related to respiration. In reality the phenomenon 

 of change is one of death, and may be compared to spontaneous coagula- 

 tion. There is no evidence of the existence of either haemoglobin or 

 hfemocyanin in the blood. 



Stigmata of Insects. 



The respiratory system of the hexapod insects has been examined 

 by Dr. O. Krancher as to a large number of species. The variation 

 of the stigmata in structure as well as other characteristics proved to 

 be very extensive, and consequently no positive generalizations could 

 be formulated. The principal conclusion was that the variations were 

 correlated with adaptation for various modes of life. The method of 

 investigation adopted by the author is detailed in his memoir. (J. K.. 

 M. S., i, 729, from Z. w. Z., v. xxxv, pp. 505-574.) 



In this connection it may be added that Dr. H. Uagen, in opposition 

 to the views of Dr. Palm^n, contends that the stigmatic cords are not 

 rudimentary and closed tubes, but functionless open ones, and that they 

 do not become completely developed during the larval stages. (Z. A., Iv, 

 404). 



Dr. O. Kraucher, in 1880 (Zool. Anz., v. 3, pp. 584-588), had grouped 

 the modifications of the stigmata known to him into two jirimary groups 

 and five secondary ones; those without lips having been referred to two 

 categories, and those with lips to three. 



An Insectarium. 



In the year 1881 the Zoological Society of London added to its rich 

 exhibition a new feature in the shape of an insectarium. No previous 

 attempt, at least on an extended scale, had been made to bring to- 

 gether a collection of living insects for popular instruction, and the 

 novel addition therefore deserves some notice. The insectarium is 

 housed in a building framed of iron and glass on three of its sides, while 

 its back is brick; the structure, however, was not expressly erected for 

 the use to which it has been put, and its interior arrangements need 

 only be considered. The insects are imprisoned in special cases, the 

 largest of which are 32 inches long and 24 wi'de, with a depth of 18, 

 Those used for the principal specimens are formed of zinc plates. 

 The upper part of each is glazed on all four sides, the top being 



