TABLE OF CONTENTS xiii 



c. Stridulating organs of the rasping type 81 



The stridulating organs of the Acridiidae 82 



The stridulating organs of the Gryllidae and the Locustidae 83 



Rasping organs of other than orthopterous insects 87 



d. The musical organs of a cicada 89 



e. The spiracular musical organs 91 



/. The acute buzzing of flies and bees 91 



g. Musical notation of the songs of insects 92 



//. Insect choruses 93 



CHAPTER III 



THE INTERNAL ANATOMY OF INSECTS 94 



I. THE HYPODERMAL STRUCTURES 95 



a. The internal skeleton 95 



Sources of the internal skeleton 95 



Chitinized tendons 95 



Invaginations of the body-wall or apodemes 95 



The tentorium 96 



The posterior arms of the tentorium 96 



The anterior arms of the tentorium 97 



The dorsal arms of the tentorium 97 



The frontal plate of the tentorium 97 



The endothorax 97 



The pragmas 97 



The lateral apodemes 98 



Thefurcae 98 



b. The hypodermal glands 98 



The molting-fluid glands 99 



Glands connected with setae 99 



Venomous setae and spines i oo 



Androconia 100 



The specific scent-glands of females 100 



Tenent hairs i oo 



The osmeteria 101 



Glands opening on the surface of the body 102 



Wax-glands 102 



Froth-glands of spittle insects . . i < >- 



Stink-glands 102 



The cephalic silk-glands 103 



The salivary glands 104 



2. THE MUSCLES 1 04 



3. THE A i IMI \ i \K-N < \\\i, VND ITS \rn- \i>\r.KS i "7 



a. The more general features "'7 



The principal divisions ' " s 



I mperf orate intestines in the larves of certain insects 1 08 



