The red spiders, as I have already stated, are not real spiders, but belong to the family Acarina or mites, a family included in the same class (the arachnida) as the true spiders, from which they may be easily distinguished by the want of any apparent division between the head and thorax and body; in the true spiders the head and thorax are united together and form one piece, to which the body is joined by a slender waist. The arachnidae are followed by the myriapoda (centipedes, etc.), and these by the insectiae or true insects. The red spiders belong to the kind of mites called spinning mites, to distinguish them from those which do not form a web of any kind. It is not quite certain at present whether there is only one or more species of red spider; but this is immaterial to the horticulturist, as their habits and the means for their destruction are the same. The red spider (Tetranychus telarius--Fig. 1) is very minute, not measuring more than the sixtieth of an inch in length when full grown; their color is very variable, some individuals being nearly white, others greenish, or various shades of orange, and red. This variation in color probably depends somewhat on their age or food--the red ones are generally supposed to be the most mature. The head is furnished with a pair of pointed mandibles, between which is a pointed beak or sucker (Fig. 2). The legs are eight in number; the two front pairs project forward and the other two backward; they are covered with long stiff hairs; the extremities of the feet are provided with long bent hairs, which are each terminated by a knob. The legs and feet appear to be only used in drawing out the threads and weaving the web. The thread is secreted by a nipple or spinneret (Fig. 4) situated near the apex of the body on the under side. The upper surface of the body is sparingly covered with long stiff hairs.--_G.S.S., in The Garden._ * * * * * THE HELODERMA HORRIDUM. The discussion of the curious lizard found in our Western Territories and in Mexico, and variously known as the "Montana alligator," "the Gila monster," and "the Mexican heloderma," is becoming decidedly interesting. As noted in a recent issue of the SCIENTIFIC AMERICAN, a live specimen was sent last summer to Sir John Lubbock, and by him presented to the London Zoological Gardens. At first it was handled as any other lizard would be, without special fear of its bite, although its mouth is well armed with teeth. Subsequent investigation has convinced its keepers that the creature is not a fit subject for careless handling; that its native reputation is justified by fact; and that it is an exception to all known lizards, in that its teeth are poison fangs comparable with those of venomous serpents.