I70 INTRODUCTION 



structures very closely together. These arrangements keep the two maxillae in as 

 close contact as possible, at the same time making the canal practically air-tight, 

 without, however, interfering with the flexibility of the whole organ. 



The proboscis of the Lepidoptera, which is sometimes very long, is rolled up 

 under the thorax when not in use. To render this possible the outer chitinous walls 

 of the laciniae are transversely striated. 



By means of this simple arrangement, says Hermann Muller ('Fertilisation,' p. 5), 

 Lepidoptera are able to penetrate flowers of the most varied forms, both fiat and 

 long-tubed, and to feed on their nectar. Peculiar stiff", pointed appendages at the 

 ends of the laciniae (Fig. 71, 3) also enable them to tear open delicate succulent 

 tissues, and they are therefore able to utilize the sap of such flowers as do not 

 secrete free nectar. That they actually make use of this apparatus has been proved 

 by direct observation, for Lepidoptera are now and then to be found sucking flowers 

 which secrete no free nectar, e.g. Cytisus Laburnum, Erythraea Centaurium, and 

 the like. At the Cape, Lepidoptera damage peaches and plums by boring through the 

 epidermis with their proboscis at spots that are quite intact (Ann. Mag. Nat. Hist., 

 London, xxiv, 1869). 



The length of the proboscis of Lepidoptera varies greatly, as the following 

 table shows: ^^_ 



Bombycidae 14 (exceptionally up to 10) 



Pyralidae 4-9 



Geometridae 4-12 



Zygaenidae 7-ii 



Noctuidae 7~i9 



Plusia gamma 15-16 



Rhopalocera 5-28 



Lycaena semiargus 7-8 



Argynnis Pales 9-10 



Vanessa Atalanta 13-14 



cardui 13-15 



urticae 14-15 



lo 17 



Papilio Machaon 18-20 



Parnassias Apollo 12-13 



Anthocharis cardamines ... 12 



Pieris brassicae 16 



napi 10-12 



,, rapae 13-18 



Rhodocera rhamni 16-17 



Coenonympha Pamphilus. . . 7 



Epinephele Janira 10 



Sphingidae 3-80 



Smerinthus tiliae 3 



Macroglossa stellatarum . . . 25-28 



Sphinx ligustri 37-42 



convolvuli 65-80 



