354 ZOOLOGY. 



treated, lived tbrougli the winter. Plant-lice wereliillei. in a liot bouse 

 by similar means. Dr. Hagen tlieretore contends against Professor 

 Metschnikoli', that fungous inoculation can be applied to practical uses, 

 •^•id that it will not be necessary to wait till the scientific meaning of the 

 phenomena involved is understood; he thinks that the plan has already 

 been successful in practice, althongh further experiments should be 

 made before any positive decision can be arrived at. 



THE GLOWWORMS AND THEIR rnOSPHORESCENCE. 



Tlie structure of the Lampyridoe and their phosphorescent character- 

 istics have been examined by Ilev. II. S. Goiham.* The conclus^ion is 

 reached that '' the sexual instinct has played a large part in molding 

 the external structure of this group of beetles, and that it is to that we 

 must look for an adequate explanation of the develoi)ment of phos- 

 j)h()rescent light, though not perhaps for its origin." The cases in which 

 both of the sexes have wings, and both exhibit also phosphorescent 

 finalities, form the larger proportion among existing species. It is con- 

 tended that in this condition the emission of light would l)e useful in 

 the sittraction of the respective sexes and bring them together in swarms. 

 Those species, however, whi<*h are regarded as being the most t3j)ical 

 of the family and in which the parts are more specialized, are such forms 

 as Lamprocera and Cladodes. In these types the phosphorescent faculty 

 has not been developed in the same x)roportion as the organs generally, 

 and the eyes, for example, are ^'reduced in a direct ratio with the light" 

 whenever the antennae are enlarged in inverse ratio to the diminution of 

 the phosphorescence. Whether the eyes develop at the exi)ense of the 

 anteniue, and are, so to speak, the receptacle of all the vital forces of 

 the head, or whether the antenuic supi>lement the loss of the other 

 organs of sense, and arc useful in detecting the presence of the female, 

 only one fact is in evidence, Avhich is that theidumosityof the anteniue, 

 in one case, and the encn^mous development of the eye, in the other, are 

 usually sexual characters predominating in the male, but sometimes 

 found in both sexes. Mr. Gorham has found that selected sj)ecies of 

 Lamp>'ridai may be grouped under three categories, viz : 



1. Species with plumose antenna?, small or moderate eyes, both sexes 

 winged, light-emitting surface confined to one or more small si)ots : 

 Lamprocera, Cladodes, Vesta, Lueidora, ThctnoJis, and McgaJophthahnus. 



3. S])ecies in which both sexes are winged; light emitted consider- 

 able, sometimes greater in the 9 ; eyes large, sometimes excessive; 

 antenuje simple, usually filitbrm : Cratomorplins, Lucernula, Aspidasoma, 

 Luc'wla, and Pltoturis. 



3. Species in which the female is apterous, or with rudimentary wings; 

 light emitted often very great in the female, and often only rudiment- 



* Gorliani (H. S.)- On tlic strnctiire of tlie Lanipyrid;s, with reference tc their i)hos- 

 phorescence. Trans. Entomolo(jical Soc, London, 1880. pp. 03-07. 



