Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/306

Rh 286 ARACHNIDA [THELYPHONIDS. does not appear that they are able to inflict any great injury with the, often formidable looking, crab-like claw with which their palpi terminate, though they can gripe and hold on firmly with them. The wound inflicted by the sting at the end of the tail is certainly more or less venomous ; the amount of venom is probably dependent on the age of the scorpion, and the season of the year ; and the effect of the sting is no doubt dependent upon the state of health, constitution, or predisposition of the person injured. Experiments, tried by Maupertuis, upon poultry and dogs stung by exasperated scorpions, resulted in their almost entire immunity from bad effects, while in Redi s experiments, the sting proved fatal in some instances to pigeons. These experiments were tried with European species of scorpion, which would probably be less veno mous than those living in tropical countries. For a recent memoir on the poison of the scorpion, and the mode in which it acts, see Dr Jousset, Ann. Ent. Soc. France, 1872, p. 151 ; also Comptes Rendus, 1870, pp. 407-411. Accord ing to Jousset, the venom acts directly upon the red globules of blood, paralysing them, so that becoming agglutinated together, they obstruct the entrance to the capillaries and stop circulation. The peasant inhabitants of Tuscany are said to handle scorpions without fear ; but this may be chiefly from a skilful mode of handling them. A scorpion does not appear to be able to move its tail or its sting in a lateral direction, nor does it strike downwards. The present writer has seen natives of Egypt handling large, and it is believed very deadly ones with impunity, but then they always held them tightly by the last joint of the tail. It was a common practice so to catch these creatures, and after breaking off the tip of the sting, to let them loose again ; but this infliction generally appeared to produce a kind of paralysis of the whole tail, and probably the poor animal would soon die. Though the well-known tale of the scorpion, when surrounded by fire, stinging itself to death, has been perpetually repeated, and has even been related to the present writer with some very minute and extraordinary details, it must be held to be merely a &quot; traveller s story.&quot; Cross-examination, in the special instance noted, very much nettled the narrator at the incredulity which led to it, but it threw more than a doubt over the conclusive- ness of the experiment narrated. Probably in some in stances the poor scorpion has been burnt to death ; and the well-known habit of these creatures, to raise the tail over the back and recurve it so that the extremity touches the fore part of the cephalo-thorax, has led to the idea that it was stinging itself. Perhaps, under the pain of scorching, there may have been convulsive efforts and movements of the highly nervous and sensitive tail in this position, and the point of the sting may even have been inserted between the articulation of the cephalo-thorax and abdo men ; and what more would be wanting to make a won der-loving traveller believe that it had really committed suicide 1 The progress of scorpions is neither rapid nor graceful; they are unable to run without elevating the tail to an erect position, which seems to be necessary to enable them to preserve their balance. CLASSIFICATION OP THE SCORPIONES. The following is Koch s systematic division of the scorpions. 1 Order SCOEPIONES. Fam. I. &quot;With six eyes, Scorpionidcs. One genus only, Scorpius (Ehrb.) Fam. II. Eight eyes, Buthides. Five genera : Buthus (Leach) ; Opislophthalmus (Koch) ; Brotheas (Id.) ; Tclcgonus (Id.) ; and Ischnurus (Id.) 1 L. Koch, Uebersicht des Arachniden Systems. Nuremberg, 1850 pp. 86-92. Fam. III. Ten eyes, Centrurides. Two genera: Centrums (Ehrb.) ; and Vaejovis (Koch). Fam. IV. Twelve eyes, Androctonidcs. Three genera : Andro- ctonus (Ehrb.); Tithyu-s (Koch) ; and Lychas (Id.) One hundred and twenty-two species, distributed variously among the above eleven genera, have been described by Koch (DicAraclm.) ; but many others also have since been added to these, in isolated papers by other authors. For another systematic arrangement, as well as on the group generally, with descriptions of seventy-eight species, see Walckenaer, 7ns. Apt., iii. pp. 14-75, where other works are also referred to. Scorpions have been found in a fossil state, as well as in amber, in which substance a species of Tithyus (T. eogcnus) has been described by Menge. Order VI. THELYPHONIDEA. The last group, Scorpiones, seems to be the culminating point of the Arachnids in a certain plane, and it presents the arachnidous type in its highest and most complex state of development. The group now to be considered gradually lowers, so to speak, this type again through its three well-marked families, to the last order Araneidea. As has been before observed, there is seldom or never in nature exactly the same hiatus between one group and another, as there may be between either of them and others; or, in other words, some groups are far more nearly allied to the one next to it than others are to that next to them, although, perhaps, all of those groups bear the same apparent value in a systematic arrangement. Thus, for in stance, the groups A, B, C, D may all be equal in a systematic arrangement, and yet A and B may be far more nearly allied than B and C ; or again, C and D may be more closely united than either B and C or A and B. So the two orders of Arachnids Scorpionidea and Thelyphomdea are certainly far more nearly allied to each other than, for instance, the Solpugidea and Scorpionidea, or the Thelyphonidea and Araneidea are to each other respectively. So obvious is the affinity of the family Thelyphonides of the present order to the Scorpiones, that Walckenaer and others have included them in the same order, making a separate order of its other family, Phrynides ; but the latter family certainly seems nearer to Thelyphonides than even the Thelyphonides to the Scorpiones; and so, while the Thelyphonides and the Phrynides must go together, these last could scarcely with any propriety be included in the same order as the scorpions. This will, we think, be evident when we consider presently their structural char acters. From these and other considerations, it has there fore been thought best to separate the Thelyphonides from the Scorpionides, and include them in another order with Phrynides. In the order Thelyphonidea, the cephalo-thorax is similar in the general nature and condition of its integument to that of the scorpions, being hard, granulose, and sometimes tuber cular, bearing also visible traces of its soldered segments. The abdomen is segmented, and united to the cephalo- thorax by a pedicle of greater or less strength, but never, as in the Scorpiones, throughout its entire breadth; it terminates in one family (Thelyphonides) with three post- abdominal segments, to which is attached a long multi- articulate setiform tail; in another (Tartarides) with a short tail of different form according to the species ; and in the third family (Phrynides) the abdomen terminates with a simple button-like segment. The legs of the first pair are much longer than the rest (in the Phrynides of most inordinate length) and antenniforni; the ^ tarsi, and generally the metatarsi, multi-articulate, ending without any terminal claw ; the legs of the other three pairs are seven-jointed, with the last, or tarsal joint, subdivided. The eyes when present (as in two families), are eight in number, placed on the fore part of the cephalo-thorax