180 



SCIENCE 



[N. S. Vol. XLIII. No. 1101 



cific, definitive environmental stimuli, but because 

 of the inherited organization and forces in the 

 oosperm, which can only be secondarily modified 

 or controlled by other factors. 



The Development of Recurrent Bronchi and of Air 

 Sacs of the Avian, Lung: Wm. A. LocT and 

 Olof Lassell, Northwestern University. 

 The notable observations of Sehulze (1911) 

 and of Juillet (1912) have brought forward a 

 newly recognized structural element — the recur- 

 rent bronchi — known only in the lungs of birds, 

 which imparts a renewed interest in the structural 

 peculiarities of the avian lung and in the physiol- 

 ogy of its air-sacs. The development of these re- 

 current bronchi, beginning as buds on the air-sacs 

 and growing into the lungs, as illustrated by the 

 lantern slides, and the condition of the recurrent 

 bronchi of the adult lung is shown by Wood 's 

 metal casts. The formation of bronchial circuits 

 within the lung by the union of recurrent bronchi 

 with branches of other bronchi is indicated, and 

 the probable physiology of the air-sacs is briefly 

 considered. 



Eegarding the development of the air-sacs, the 

 interclavicular is shown to arise from four sepa- 

 rate moieties, two from each lung, which later 

 unite to form the single median sac of the adult. 

 The lateral moieties of the interclavicular sac have 

 long been recognized, but the existence of separate 

 mesial moieties and the manner of the union of the 

 four parts is believed to be presented for the fiirst 

 time. 



COMPARATIVE ANATOMY 



The Olfactory Organs of Lepidoptera: N. E. Mc- 



INDOO, Bureau of Entomology. 



The organs discussed in this paper are the 

 olfactory pores, already described by the writer 

 for the Honey Bee, Hj-menoptera and Coleoptera 

 in other papers. The present paper deals with 

 only the morphology of these organs in Lepidop- 

 tera. 



As usual, the olfactory pores are found on the 

 legs, wings and mouth-parts. Two groups are al- 

 ways present on each trochanter; one group 

 usually on each femur; a few scattered pores gen- 

 erally on each tibia, some of these sometimes be- 

 ing in the tibial spines; one to four groups on the 

 base of each wing, besides scattered pores usually 

 extending the full length of the wing; and a few 

 pores on the mouth-parts. 



The total number of olfactory pores varies from 

 about 500 to 1,300. Moths usually have more porea 

 than butterflies. Based on the total number of 



pores, the individual, sexual and specific differences 

 are slight, while the generic differences may or 

 may not be slight, the latter differences depending 

 on the sizes of the specimens compared. 



The olfactory pores are flask-shaped structures, 

 and those on the wings have been called dome- 

 shaped organs because the chitin surrounding each 

 pore aperture is arched dome-like above the gen- 

 eral surface of the wing. As usual, ohitinous eones 

 are present and the sense cells are spindle-shaped. 

 In distribution and structure the olfactory pores of 

 Lepidoptera are more similar to those of Hymenop- 

 tera than to those of Coleoptera. 



The Structure of Agelacrinites, a Fossil Echino- 

 derm (Cistoid) of the Biehmond (illustrated 

 with lantern) : S. R. Williams, Miami Univer- 

 sity. 



1. Agelacrinites was probably somewhat mo- 

 tile — at least able to adapt its peripheral rim to its 

 surroundings. 



2. The peripheral rim may have been extensible. 



3. The animal probably breathed by muscular 

 protraction, extension and retraction of the anal 

 pyramid, getting oxygen by rectal respiration. 



4. The probable path of the alimentary canal 

 in the young animal. 



5. Cover plates and floor plates of the brachial 

 grooves and their patterns. 



Neuromeres and Metameres: H. V. Neal, Tufts 



College. 



The paper summarizes observations upon the 

 nidular relations of cranial nerves in Squalus em- 

 bryos and raises the problem, Are neuromeres re- 

 liable criteria of the primitive metamerism of the 

 vertebrate head? 



The motor nidulus of the trigeminus lies in the 

 second and third hind brain neuromere (rhom- 

 bomere) ; that of the facialis extends through 

 four rhombomeres, viz., the fourth, fifth, sixth 

 and seventh. The nidulus of the glossopharyngeus 

 lies in the sixth and seventh rhombomeres, while 

 that of the vagus extends from the posterior part 

 of the seventh for a considerable distance in the 

 unsegmented portion of the medulla. 



Of the somatic motor nerves, the nidulus of the 

 oculomotorius lies in the midbrain; that of the 

 trochlearis lies primarily in the first (cerebellar) 

 rhombomere; that of the abdueens extends through 

 the sixth rhombomere and somewhat into the two 

 adjacent ones. The nidulus of the hypoglossus 

 lies in the unsegmented portion of the medulla 

 posterior to the seventh rhombomere. 



Somatic motor niduli lie primarily dorso-lateral 



