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SCIENCE 



[N. S. Vol. XXIX. No. 748 



connection with the latter nerve. The pineal stalk 

 is innervated by a bundle of about thirty fibers 

 connecting with the brain just caudad of the 

 habenular body. Intravitam methylene blue 

 preparations of the stalk of the epiphysis show 

 ganglion cells with an interlacing plexus of fibers 

 very similar to the sympathetic innervation of 

 the walls of the intestines of vertebrates. 

 Effects of Brachycephaly and Dolichocephaly upon 

 the Teeth of Man: Raymond C. Osbukn, Bar- 

 nard College, Columbia University. 

 A study of various types of skulls to show the 

 variations in the dental arch, and especially in 

 the teeth themselves. The principles which have 

 been stated by Professor H. F. Osborn (Bui. Am. 

 Mus. Nat. Hist., Vol. XVI., art. 7) as operating 

 in various groups of lower mammals are here 

 shown in man within the limits of a single species. 



Some Noteworthy Additions to the Bryozoan 



Fauna of our Atlantic Coast: R. C. Osbueu, 



Columbia University. 



A series of lantern slides showing various fam- 

 ilies, genera and species of Bryozoa new to our 

 east coast fauna. A preliminary report of certain 

 of the more striking forms collected by the author 

 at the Tortugas, Beaufort and Woods Hole sta- 

 tions. 

 Fission and Regeneration in Sagartia lucice: 



D. W. Davis, Sweet Briar College, Va. 



The sexually derived, undivided individual in 

 S. lucice is probably a regular hexamerous form 

 with six pairs of complete mesenteries. Of these, 

 two pairs situated at opposite ends of the major 

 transverse axis are directives and each directive 

 pair is associated with a siphonoglyph. A sec- 

 ondary cycle, of incomplete mesenteries arranged 

 in pairs, alternates with the pairs of the first 

 cycle. A third cycle is usually present, and even 

 a fourth may be represented. Longitudinal divi- 

 sion is so common that such undivided animals 

 are rare, and fission followed by regeneration 

 plays an important part in the life-history. Fis- 

 sion occurs, almost without exception, in endo- 

 ccels and, in about two thirds of the cases exam- 

 ined, in complete endocoels. The fission-plane 

 shows a decided tendency to pass at right angles 

 with the major transverse axis, producing bilat- 

 erally symmetrical pieces, but with little regard 

 to an accurate halving of the dividing animal. 



In regeneration, from eight to ten complete 

 mesenteries are formed, the precise number de- 

 pending upon the complete or incomplete char- 

 acter of the mesenteries at the boundaries of the 

 old part. The new mesenteries are formed in a 



characteristic succession not harmonizing with an 

 Edwardsia type of development but corresponding 

 to the order described by the Hertwigs for two 

 (possibly regenerating) specimens of Adamsia. 



Reactions of the Dogfish to Chemical Stimuli: 

 R. E. Sheldon, University of Chicago. 

 The smooth dogfish, Mustelus oanis (Mitch.), 

 was tested over the entire body surface, mouth, 

 spiracle and nostrils with acid, saline, alkaline, 

 sweet and bitter substances. The fish was found 

 to be very sensitive over the entire surface to 

 acids and alkalis in very dilute solution. It is 

 less sensitive to salts and bitter substances and 

 does not react at all to sweet solutions. The 

 general body surface, particularly the fins, are 

 more sensitive to alkalis and salts than is the 

 mouth; both are equally sensitive to acids, while 

 the mouth is the more sensitive to bitter sub- 

 stances. When the spinal cord is destroyed no 

 reactions are obtained from the caudal part of 

 the body, showing that the lateral line nerves 

 have nothing to do with these reactions. When 

 the cord is severed from the brain, the caudal 

 part of the animal is more sensitive than before 

 to chemical stimuli. There is no spinal shock 

 after section of the cord. The nostrils are very 

 sensitive to alkalis, acids, salts and bitter solu- 

 tions. Section of the olfactory crura and different 

 rami of the trigeminus nerve showed that this 

 sensitiveness is due to the maxillaris nerve rather 

 than the olfactory. Parts of the body were over- 

 stimulated for tactile response, after which they 

 could always be stimulated chemically. When 

 any region was overstimulated for any given 

 chemical, as an acid, it rarely responded to tactile 

 stimuli, although it usually responded to other 

 chemical stimuli, as a saline or alkaline solution. 

 When cocaine was applied to the skin, tactile re- 

 sponse disappeared before chemical. Among the 

 different chemical senses, bitter disappeared first. 

 This sensitiveness to chemical stimuli is due al- 

 most exclusively to the nerves of general sensa- 

 tion, not at all to the olfactory nerve and very 

 little, if any, to the gustatory nerves. 



Ohondrocranium of an Embryo Pig: Chas. S. 



Mead, New York City. 



The study of the chondrooranium of Sus is of 

 value not only in assisting us to understand the 

 structure of the adult skull in this form, but also 

 on account of its bearing on the general mor- 

 phology of the mammalian cranium. Owing to its 

 relatively low position in the ungulate series, we 

 would expect many primitive characters to be 

 retained in its cartilaginous cranium, and indeed 



