2i8 VENOMOUS ANIMALS : PROTOZOA TO ARTHROPODA 



places, especially in woods. The poison apparatus of the centipedes 

 is formed by the appendages of the first trunk segment being 

 modified so as to form a large pair of jaws, at the base of which 

 the poison gland lies. The duct of this gland opens on the apex of 

 the claw, and therefore, as there are two jaws, a centipede-bite will 

 show two minute punctures or drops of blood. 



The venom is primarily intended to kill their prey, which consists 

 of small insects and larvae. 



Geographical. — The most noted species are Scolopendra cingulata, 

 France, Spain, Italy; 5. gigantea Koch, S. morsitans L., 5. heros, 

 Africa, India, Indo-China, Equatorial America; Geophilus longicornis 

 Leach, Mid-Europe. 



The Venom. — The venom is an acid opalescent liquid, but little 

 miscible with water. For experimental purposes it can be obtained 

 by treating the lower lip and the hooks with normal saline solution. 



When injected into the veins of rabbits, it causes an immediate 

 paralysis, with coagulation of the blood, while under the skin it 

 forms a large abscess. 



Effects of the Venom.— The poison causes local and general 

 symptoms. At first there is itching, but this is quickly followed 

 by intense pain, which extends all over the limb. A red spot 

 appears at the site of the bite, which enlarges and becomes black 

 in the centre, and sometimes there are lymphangitis and lymph- 

 adenitis. The general symptoms are great mental anxiety, vomit- 

 ing, irregular pulse, dizziness, and headache. 



Diagnosis. — ^The diagnosis is obtained by the history and the 

 presence of the two minute punctures. 



Prognosis. — The prognosis is good, though small children have 

 been known to die from the effects of a sting. Adults, as a rule, 

 recover in about twenty-four hours at the most. 



Treatment. — Bathe the part well with a solution of ammonia 

 (i in 5 or i in lo). After bathing, apply a dressing of the same 

 alkali, or if there is much swelling and redness, an ice-bag. 



If necessary, give hypodermic injections of morphia to relieve the 

 pain. At a later period, fomentations may be required to reduce 

 the local inflammation. 



3. Hexapoda. 



The Hexopcda, or insects, contain many species injurious to man. 



The orders to which the principal venomous species belong are: 

 (i) Anopleura; (2) Hemiptera; (3) Hymenoptera; (4) Lepidoptera; 

 (5) Diptera; and (6) Coleoptera. 



I. Anopleura. 



This order includes the lice, which cause much irritation by their 

 bites. The nature of the venom, however, is not known, and the 

 lice are of more importance as carriers of disease, and will therefore 

 be dealt with more fully in Chapters XXX. (p. 749) and XXXV. 

 (p. 872). . , ^ 



