94 REPORT OF THE SECRETARY. 



The classification used was that adopted in the national collection. 



Utilization of mollusks. — This series included pearls, cameo shells of various sorts, 

 specimens illustrating the formation of pearl in the shell, both fresh- water and 

 marine pearl mussels deprived of their outer coating so as to show the pearly 

 substratum, and manufactured articles, such as buttons and other objects, made 

 from pearl-bearing shells, of which specimens both in the natural condition and 

 decorticated — so as to show the shelly layer — and in the manufactured state, were 

 exhibited. 



Byssus of the "wing-shell." — A somewhat rare object was a glove resembling silk 

 woven by the nuns of Naples from the silky byssus of the pinna, or " wing-shell," 

 of the Mediterranean. 



In one of the windows was a transparency of a cuttle fish, Octopus verrucosus, and 

 suspended from the ceiling were life-size models of an octopus and of the giant squid, 

 Architeuthis harveyi. 



The selections for the exhibit were made by Mr. C. T. Simpson under the direction 

 of Mr. W. H. Dall. 



Department of insects. — This display occupied one side of two cases, and was 

 included in sixteen trays. It was, of course, very far from complete, either as an 

 exhibit of insects or as an illustration of the wealth of material in the entomological 

 collections of the Museum. Two different series were, however, shown — a systematic 

 series, and a series illustrating protective and aggressive resemblance aud mimicry, 

 (the imitation, by insects, in form and color, or both, of objects met with in their 

 surroundings, and the imitation of the form and color of other insects). 



Systematic series. — This series was included in twelve trays, aud re2)resented the 

 more conspicuous insects of Tennessee and neighboring States, arranged according 

 to their scientific classification. The Lepidoptera was more fully represented than 

 any other order, since the species are generally large and showy, and well adapted 

 for exhibition purposes. Six trays were devoted to this order. The modern orders 

 corresponding to the older order Neuroptera were exhibited in one tray, and the 

 remaining five trays were taken up with the orders Hymenoptera, Coleoptera, 

 Hemiptera, Diptera, and Orthoptera. All of the smaller species were omitted, as 

 they could be represented adequately only by means of enlarged drawings or models 

 for the preparation of which funds could not be provided. 



Protective and aggressive resemblance and mimicry. — This series occupied four trays 

 and was divided into seveu groups. It consisted of specimens illustrating the 

 following phases of resemblance and mimicry : 



(1) General protective resemblance (insects having a general resemblance in color 

 to their surroundings). 



(2) Special protective resemblance (insects resembling objects in their surround- 

 ings, both in form and color). 



(3) General aggressive resemblance (carnivorous insects having a general resem- 

 blance to their surroundings in color, thereby enabling them to more easily approach 

 their prey). 



(4) Special aggressive resemblance (carnivorous insects resembling in form and 

 color some special object in their surroundings). 



(5) Protective mimicry (insects which for their own protection mimic other insects 

 having some special means of defense, such as a sting or noxious odor, and which 

 for that reason are avoided by birds, lizards, etc.). 



(6) Aggressive mimicry (insects which resemble other insects in order to approach 

 or cohabit with them, either preying directly upon them or as parasites upon their 

 larv»). 



(7) Warning colors (insects which are already protected by a sting or in some 

 other way, but which have, in addition, some bright or conspicuous color, in order 

 to warn insectivorous animals from attacking them). 



The collections were arranged by the late Mr. Martin L. Linell, under the direc- 

 tion of Dr. L. 0. Howard. 



