ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 41 



antennas. He calls attention to the composition of the head out of six 

 metameres, plus an acron innervated by the frontal regions. There are 

 curious inverted tracheae which traverse the tracheal sacs and contain a 

 nerve, and it may be also muscles and the aorta. In a previous paper * 

 Janet described the remarkable umbel-shaped and setiform structures 

 on the mandible of the bee. 



Organs of Flight in Hornet.t— E. Groschel has made an elaborate 

 study of Vespa crabro as regards the organs of flight. He deals with 

 the skeleton of the thorax, and with the wings and their muscles. In 

 connexion with the wings, he describes the tegulse — convex plates which 

 cover the joint of the anterior wings ; the pteralia — small pieces belong- 

 ing to the joints between wings and thorax, and those parts of the thorax 

 which share in making the joints. The movements of the wings are 

 described, and notice is taken of the various air-sacs or dilatations of 

 the trachea?. 



Fossil Wasps' Nests. J — Anton Handlirsch describes from the Upper 

 Oligocene of Florsheim a number of objects about the size of hazel-nuts 

 which appear to be nests of a solitary wasp {Eumenes rbmeri sp. n.) allied 

 to but much larger than the common Yiuxo'^QdiU. E. pomiformis. The 

 walls consist of clay, with some grains of calcareous sand. 



Eyes of Butterflies.§— W. Johnas has studied the compound eye in 

 over sixty species of Macro- and Micro-Lepidoptera, The uniformity of 

 structure is very striking. There is a continuation of the rhabdom into 

 the sheath of the crystalline cone, and a cup-like enclosure for the apex 

 of the crystalline cone. The differentiation of the " Stiftchensaume," 

 and the associated formation of the rhabdome occurs at a certain distance 

 frona the basal membrane. Thus a cavity arises in the retinula, into 

 which pigment may penetrate from below the basal membrane. There 

 are usually eight retinula cells, but there may be ten. In some day- 

 flying offshoots from nocturnal types, the formation of pigment within 

 the corneal facets and other adaptations may serve to screen the bright 

 light. Diplacement of pigment was experimentally proved only in some 

 nocturnal types exposed to artificial light. The author has re-discovered * 

 the tapetum within the retinula, which was described by Leydig and 

 Schultze. 



Innervation and Sense-organs of the Wing in Lepidoptera.|l— R. 



Vogel has studied the distribution of nerves in the wing, the structure 

 and distribution of the sensory papillae, of the sensory scales, of the 

 sensory spines (or " marginal nervure hairs "), and of the chordotonal 

 organs. Three nerve-branches enter the base of the wing. The sensory 

 scales are tactile, and the same is probably true of the sensory spines. 

 It may be that the papillae have to do with orientation or equilibration 

 in flight, but their function, like that of the chordotonal organs, remains 

 quite uncertain. 



* Comptes Rendus, cli. (1910) pp. 618-21 (1 fig.) 



t Arch. Naturges., Ixxvii. (1911) pp. 42-62 (2 pis.). 



% Ber. Senckenberg. Nat. Ges., No. 41 (1910, received 1911) pp. 265-6 (1 fig.). 



§ Zeitschr. wiss. ZooL, xcvii. (1911) pp. 218-61 (3 pis. and 3 figs.). 



II Zeitschr. wiss. Zool., xcviii. (1911) pp. 68-134 (3 pis. and 14 figs.). 



