186 



A R A L I A C E JE. 



ancc, that, at the last meeting of the British Associa- 

 tion for the Promotion of Science at Cambridge, the 

 inquiry as to the true male organs of generation in 

 the spiders was. one of the three questions proposed 

 relative to the annulose animals. 



The development of the embryo of the spiders 

 has been traced in a most elaborate manner by 

 M. Heroldt, of which a notice will be found in the 

 Insect Transformations, pp. 123 and 124. (Untersuch 

 ungen iiber die Bildungs-geschichte dir Wirbellosen 

 Thaere im Eie. Marburg, 1824.) 



From various observations, it is evident that the 

 limbs of the arachnida are capable of reproduction 

 when mutilated. This faculty, together with the 

 longevity of some species, various peculiarities of 

 structure, and especially the circumstance that some 

 spiders engender more than once during the course 

 of their lives, evidently prove the distance which 

 exists between this class and the insects, and their 

 greater proximity with the Crustacea. 



The habits of the arachnida exhibit much of 

 popular interest, but as they vary greatly in the 

 different families, it will be more convenient to notice 

 them under the head of each group. 



As to the classification of this class, it is to be 

 observed, that we are indebted for the most part to 

 the works of foreigners for those views which have 

 been adopted in the modern arrangements of the 

 annulose animals. In the work of our countryman, 

 Lister, published in 1678, " Historic Animalium 

 Angliae tractatus de Araneis," are, indeed, to be 

 found many very good coloured figures of British 

 spiders, as well as the first attempt at their distribution ; 

 but until within the last few years, arachnology seems 

 to have been banished from the studies of British 

 naturalists, and taken up its abode in France, where, 

 under the hands of Savigny, Latreille, and, above all, 

 the baron Walckenaer, it has arrived at a high state 

 of cultivation. We may now, however, boast of the 

 labours of Blackwall, published in the Linnaean 

 Transactions and the Annals of Philosophy, as well 

 those of an anonymous writer in a late number of 

 the Magazine of Natural History, from whose admi- 

 rable pencil and pen, British arachnologists may 

 shortly hope to be furnished with a most invaluable 

 series of memoirs. 



The class, as at present constituted, has generally 

 been divided into two orders, the pulmonary and the 

 trachean arachnida ; but in his last work, Latreille 

 has established a third order, Aporobranchitz, for a 

 very remarkable group of animals, which Leach 

 regarded as possessing so doubtful a situation, that in 

 the Entomologists' Compendium, they were placed at 

 the end of the true insects. 



The class may therefore be thus distributed. 



SECTION I. Puhnonaria, having pulmonary sacs 

 for respiration, with six or eight simple eyes, con- 

 sisting of two orders. 



ORDER 1. The Dimerosomata of Leach, or the 

 Araneides of Latreille, consisting of the great group 

 of spiders, divisible into various families, having the 

 abdomen attached by a foot-stalk, and not articulated. 



ORDER 2. The Polymer osomata of Leach, or the 

 Pedipalpi of Latreille, consisting of the scorpions, 

 and divisible into two families, Scorpionidce and Phry- 

 nidcc, having the abdomen attached by its whole 

 breadth, and composed of numerous segments. 



SECTION II. Trachcaria, having tracheae for 

 respiration, never with more than four eyes, con- 

 sisting of two orders. 



ORDER 3. Adelarthrosomata *, or those trachean 

 species which have the mouth furnished with visible 

 didactyle chelicera, and the abdomen annulated, 

 although occasionally in an indistinct manner. 



Consisting of the families So/pugidte, Chclifcridce, 

 and Phalangiid(e, or harvest spiders. 



ORDER 4. Monomerosomata of Leach, or those 

 trachean species which have the body formed of a 

 single segment, the abdomen presenting no traces of 

 articulation, and the mouth either suctorial or fur- 

 nished with concealed didactyle chelicera. This 

 order consists of the very extensive Linnsean genus 

 Acarus, or mites, divisible into various families. See 

 the article ACARI. 



SECTION III. (ORDER 5.) Podosomata of Leach, 

 or the Aporobranchia of Latreille. These singular 

 insects are marine, they are not furnished with 

 distinct spiracles, so that it is probable that respira- 

 tion is effected by portions of the external covering 

 of the body possessing the properties of branchiae. 

 The body is linear, and seems, as it were, to be com- 

 posed only of the union of the legs ; the mouth is 

 tubular and porrected ; and the females are furnished 

 with an additional pair of legs, which serve only for 

 carrying the eggs. This order consists of two families, 

 Pycnogonidce and Nymphorudee. 



ARALIACE^E or ARALI^E. A natural family 

 of plants, the ninety-ninth order of the Jussieuan 

 system, comprising seven or eight genera, and up- 

 wards of forty-three species. This family has a con- 

 siderable resemblance to the umbelliferous tribe, 

 from which it is distinguished by its many-celled 

 fruit, and shrubby habit. The botanical characters of 

 the family are : calyx inferior ; petals five or six ; 

 stamens equal in number to the petals ; anthers two- 

 celled ; ovary two or more celled ; styles many, 

 simple ; berry two to fifteen celled ; generally trees 

 or shrubs, rarely herbaceous plants : flowers small, 

 collected into umbels, and^provided with involucres. 



PANAX QUINQUEFOLIUM. a, hermaphrodite flower; b, male 

 flower ; c, calyx and pistils ; d, section of tbc ovary; c, section 

 of the fruit, showing the seeds. 



This is a small order, containing plants which are 

 not remarkable for the beauty of their flowers, al- 

 though the foliage of many is extremely fine, as seen 

 in the species of sciadophyllum and ivy The plants 

 of this order are found in India, China, North 

 America, and Europe. In their general properties 

 also they resemble the umbelliferae, being stimulant, 

 aromatic, and occasionally narcotic. ' They differ, 

 however, from the umbelliferae in the qualities of their 

 seeds. The roots of most of the Araliacea? have a 

 sweet aromatic flavour. Those of the Aralia raceuwsa 

 and nudicau/is, resemble the parsnep in taste. The 

 roots of the latter species are brought from North 

 America, and sold as a substitute for sarsaparilla. 



* In order to preserve the order of the mites entire, as 

 suggested by Dr. Leach in the Supplement to the Encyclo- 

 pedia Britannica, we have been compelled to establish a 

 new order for the reception of the remainder of the trachean 

 species, which \ve have named from the comparatively obscure 

 articulation of the abdomen. 



