Februaky 21, 1913] 



SCIENCE 



309 



toith a consideration of the Homologies existing 

 between the Appendages of the Hexapoda. 

 The question as to the homologies existing 

 among the paired appendages of the Hexapoda 

 has received attention from various investigators, 

 and in particular from Hansen, Heymons, Borner, 

 Verhoeff and Escherig, none of whom, however 

 have progressed far toward a satisfactory solu 

 tion of tlie problem. In general it has been ac 

 eepted that the stipes and mentum corresponded 

 to the thoracic and abdominal eoxse while the 

 maxillary and labial palpi were equivalent to the 

 trochanter, femur, etc., of the functional leg. 



Studies on Bhyparobia maderw, the ' ' giant cock- 

 roach" from Panama, particularly of 10 mm. and 

 12 mm. embryos, as well as other investigations 

 in connection with the appendages of the Thysan- 

 ura, make it evident that the typical appendage 

 (mouth parts, thoracic, abdominal, caudal) of the 

 Hexapoda consists of seven definite areas best 

 represented by the maxillae with the galea, lacina, 

 ectostipe,' endostipe, ectocardo, endocardo and 

 palpus. Furthermore, the palpus should be homol- 

 ogized with the stylus of the thoracic and abdom- 

 inal eoxse and not with the functional leg, inas- 

 much as both palpus and stylus are appendages 

 of homodynamous areas (ectostipe, eetomentum, 

 meron) while the leg is an appendage of the area 

 (endocoxa) corresponding to the endostipes. 



The facts noted suggest the origin of the bira- 

 mose appendage of the Hexapoda directly from 

 the parapodinm of the Polychsita, the notopodium 

 and neuropodium arising in connection with the 

 dorsal and ventral bundles of setae and corre- 

 sponding to the outer (eetal) and inner (endal) 

 groups of sclerites as outlined above. It would 

 thus appear that the Arthropoda are a polyphyletic 

 group, and that the relationship between the ap- 

 pendages of the Hexapoda and Crustacea is a 

 more remote one than generally accepted in con- 

 nection with the studies of Hansen and Borner. 



The historical development of the problem as 

 well as the presentation of the facts which would 

 seem to establish the views here advanced, will 

 appear in the completed paper, of which this is a 

 partial summary. 



James Zetek, Sanitary Commission Canal Zone : 



'■ The prefixes ' ' ecto ' ' and ' ' endo ' ' have been 

 utilized in an attempt to establish a better nom- 

 enclature, while minor changes have been made in 

 the terminology of older parts, e. g., ' ' ectostipes ' ' 

 is a more cumbersome term than ' ' ectostipe. ' ' 



Determining the Flight of Mosquitoes. Read by 



title. 

 William A. Riley, Cornell University: Some 



Sources of Laboratory Material for Work on 



the Melation of Insects to Disease. 



The demand for at least elementary courses on 

 the relation of insects to disease brings up the 

 question as to available laboratory material. 

 There is comparatively little difficulty in obtaining 

 the parasitic mites, ticks, lice, house-flies, mosqui- 

 toes and fleas in their various stages, but it is 

 usually assumed that most of the pathogenic Pro- 

 tozoa are tropical species and that nothing can be 

 substituted for them in laboratory work. As a 

 matter of fact, a number of insect -borne Protozoa 

 and worms occur in this country and, together 

 with other blood parasites whose life-history is less 

 better known, are available for laboratory work. 

 The species discussed were Trypanosoma leivisi, a 

 widely distributed parasite of brown rats; Trypan- 

 osoma rotatorium from the frog; the related 

 Crithidia from the "sheep tick"; Berpetomonas 

 from the house-fly; Monocystis from the seminal 

 vesicles of the earthworm as introductory to the 

 study of the Haemosporidia ; Lankesterella ran- 

 arum, Swmogregarina sp. ; Proteosoma, JBalter- 

 idium, Babesia hilaria in the blood of the crow 

 and English sparrow, and Dipylidium caninum, 

 the double-spored tapeworm of dogs, cats and 

 man. 



Y. H. Tsou and S. B. Tracker, University of 

 Illinois: The Homology of the Body Setce of 

 Lepidopterous Larvce. 



This paper consisted (1) of a statement of the 

 ditficulties involved in homologizing the body setae 

 of these larvae, (2) of a consideration of the 

 serial homology of the setaa of the different seg- 

 ments and (3) of the specific homology in the 

 larger groups. Greek letters were employed to 

 designate the setae in order to obviate the eon- 

 fusion which has arisen from the use of numbers 

 in different ways by different authors. The pro- 

 thorax of Hepialus was shown to represent the 

 primitive arrangement of seta; and was used as a 

 type for determining the homology of the setae on 

 the different segments. The authors had studied 

 many species and gave figures of four: Hepialus 

 lectus and H. humuU of the Jugatas, Pseudano- 

 phora arcanella of the Tineidae and Mamestra 

 picta of the Noctuids. Each of these was com- 

 pared with the type, segment for segment. This 

 is the first time the setae of the prothorax have 

 been homologized with those of the other segments. 



