982 



SCIENCE. 



[N. S. Vol. XVII. No. 442. 



Likewise Paramcecia which in an acid culture 

 are positive to the electric current may be 

 made to reverse their reaction by gradually 

 neutralizing the acid with sodium hydrate. 

 Lillie has observed a similar relation between 

 the response to the electric current and the 

 condition of the protoplasm, whether acid or 

 alkaline, in his experiments upon nuclear and 

 cytoplasmic structures cited above. He showed 

 that nuclear structures, which contain a large 

 amount of nucleic acid, move toward the 

 anode, while cells very rich in cytoplasm, 

 which is basic in reaction, move in an opposite 

 direction when exposed to the electric current. 



It thus appears, from the experiments on 

 Paramcecia here outlined, that the conclusions 

 suggested by the work of Mathews and of 

 Lillie are capable of a wider application than 

 has heretofore been given them, and that a 

 definite relation exists between the sign of the 

 charge carried by the protoplasmic particles 

 and certain external conditions surrounding 

 the organism. It also follows from the ex- 

 periments that by varying these external con- 

 ditions, we are able not only to reverse the 

 charge carried by the protoplasmic particles, 

 but also the response of Paramcecium to cer- 

 tain forms of chemical and electrical stimuli. 

 A. W. Greeley. 



ZooLOGiCAi, Laboratory, 



Washington University, St. Louis, Mo., 

 May 19, 1903. 



NOTES ON ENTOMOLOGY. 

 Mr. W. L. Tower has given an account of 

 the origin and development of the wings of 

 coleoptera.* It. is illustrated by seven plates 

 and figures in text. The studies were based 

 on species of various families (mostly phyto- 

 phagous). He believes that the elytra are 

 homologous to the forcrwings of other insects, 

 the only logical position. As to the origin of 

 the wings his studies lead him to accept Ver- 

 son's view that the wings are derived from the 

 rudiments of the meso- and metathoracic 

 spiracles. Verson's theory was published in 

 1890, and based on his study of the silk-worm 

 {Bombyx mori). Very substantial objections 



* Zool. Jahrb., Abth. f. Aiiat., 17 Bd., pp. 317- 

 572, 7 pis. 



are advanced by Tower to the two other 

 theories of wing-origin, that of the tracheal- 

 gill origin and that, as prolongations of the 

 thoracic tergum. However, his evidence does 

 not show that the ancestors of the Pterygota 

 were terrestrial, and not aquatic. 



In a recent number of the BericM uber 

 Land- und Forstwirthschaft im Deutsch-Osta- 

 frika are two articles of an entomological na- 

 ture. One by V. Lommel on the tsetse-fly,* 

 deals with the distribution of this pest in 

 East Africa, and its habits. The other is by 

 Dr. A. Zimmerman f and treats of African 

 coffee insects. The m.ost injurious specie's is 

 the common coffee leaf -miner (Gemiostoma 

 coffeella). An unnamed pentatomid does con- 

 siderable injury to the coffee beans by punctur- 

 ing them; quite possibly it gives entrance to 

 some fungus. It seems strange to see a work 

 published in Germany with good figures of 

 insects but without their scientific names, 

 which could easily have been supplied by Ger- 

 man entomologists. 



The last number of ' Fauna Arctica 'X con- 

 tains articles on the hyxaenoptera, hemiptera 

 and siphunculata of the Arctic regions. The 

 former is by Kiaer and Friese, the latter two 

 by Breddin. There is a good bibliography, 

 and many notes on distribution and time of 

 flight in bees. ISTo new species are described; 

 but there is a fine colored plate representing 

 sixteen species of Bombiis. 



Dr. Otto Schenk, of Jena, treats of the sense 

 organs on the antennal surface of some 

 lepidoptera and hymenoptera.§ He considers 

 the sexual differences in the antennse of these 

 insects, the structure of the sense organs and 

 their probable function. He arranges these 

 sense organs in several classes, and concludes 

 that most of them are for the detection of 

 odors ; but that the sensilla ampullacea or ' pits 

 of Forel,' are probably hearing organs. 



Dr. L. Melichar has recently completed his 

 monograph of the Flatidse of the world. || 



* Bd. 1, Heft 4, pp. 34-350, 1903. 



t rbid., pp. 358-374, 1 pi. (colored). 



i ' Fauna Arctica,' IL, Lief. III., December, 1902. 



?( Zool. -Jahrb., Abth. f. Anat., 17 Bd., pp. 573- 

 610, 2 pis. 



, II ' Monographie der Acanaloniiden und Flatiden,' 

 Ann. Natiirhist. Hofmuseums, Wien, 1902. 



