ZOOLOGY. . 491 



the Theridiidse a beautiful instance of mimicry is furnished by the ap- 

 propriately named Formkina mutinensis. On elm trees resorted to by 

 ants of the geiiem Lasiiis and Formica, an ant-like spider named Lascmla 

 procox occurs, but " as the mimicry is exhibited only by the developed 

 males, which eat but little, the resemblance must be" in this case 

 " purely protective." 



The spider families Thomisidw and Epeiridw do not furnish any exam- 

 ples of such mimicry, and indeed, according to Professor Bertkau, in 

 those spiders "ant mimicry seems impossible." (Verhandl. naturh. 

 Verein Rheinlauds, xliii, pp. 66-69 ; J. E. M. S. (2), vi, p. 977.) 



Insects. 



Fnfomogenoiis fungi. — Insects are not rare in which appendages of a 

 cottony or silky structure, or rather reminding one of such, and borne 

 on long i^eduncles, are seen growing through the joints of the body. 

 These appendages are really fungi of various kinds. A genus of large 

 size, and which, to a considerable extent, flourishes upon insects of 

 various kinds, is the genus Cordyceps. Forty-seven species of this 

 genus have been recorded by Professor Saccardo, of winch twenty three, 

 or about 50 i)er cent., are found in larvae, and sixteen, or about 33 per 

 cent., in perfect insects. In fact, the fungus is not so common in perfect 

 insects as in the larvoe. Of the sixteen species occurring on the imago 

 or i)erfect insect noticed by Saccardo, three are noted as having been 

 found upon various species of ants; they are (1) Cordyceps unilateralism 

 found on the Atta, ceplialota of Brazil; (2) Cordyceps australis on Pachy- 

 condyla striata, also of Brazil; and, (3) Cordyceps my rmecophila on Myr- 

 mica rnfa (as well as on an ichneumon and a beetle), in North America, 

 Europe, Ceylon, and Borneo. The Cordyceps nnilateralis has been also 

 found infesting another ant of Brazil, as well as two species collected 

 by Mr. A. E. Wallace at a village on the island of Celebes. The Bra- 

 zilian ant is Formica sexguttata. Eecently a new forraicogenous spe- 

 cies of the genus, named Cordyceps Uoydli, has been described by Mr. 

 William Fawcett; the ant on which the new Cordyceps was found has 

 the appearance of being attacked by the fungus while it was alive. 

 The growth of the fine threads of the mycelium through the body 

 would in time kill it. (A. & M. Nat. Hist. (5), xviii, pp. 316-318.) 



Luminous beetles. — Among the elateroid beetles are some conspicu- 

 ous for the light which emanates from their bodies. These luminous 

 elaterids, according to Mr. E. Dubois, are the animals " which best 

 lend themselves to physiological analysis," and consequently facts bear- 

 ing upon the general theory of biological luminosity may be gathered 

 from them. The luminous elaterids are mostly found between 30° south 

 and 30° north latitude and between 40° and 180° of longitude. "The 

 emission of light is intimately connected with an important physiologi- 

 cal function, but in some rare cases there is no luminosity. The posi- 



