IM 



SCIENCE. 



[Vol. II., No. 26. 



may take place not only through the walls of the 

 alveoli, but also through the trachea, with the pro- 

 duction of emphyaema of the subcutaneous cellular 

 tissue of the neck, which in time may spread as far 

 as the extremities of the body. The peculiar pains 

 in the chest which sometimes follow upon violent ex- 

 piratory efforts may be owing, they think, to a small 

 escape of air into the pleural cavity. So many hither- 

 to inexplicable cases in which, after sudden death, 

 air has been found in the heart or pleural cavity, 

 although there was no evidence of any rupture, 

 may be explained in this way by the escape of air 

 through the lung-tissue. — {Pfliiger's archiv, xxxi. 

 160.) w. H. H. [160 



Structureless basal substance. — The structure- 

 less substance which forms the basis of the ' jelly ' in 

 medusae, Emery thinks, is still represented in the 

 higher animals, preceding in certain places the true 

 connective tissue. Emery employs the name given 

 by Hensen, ' tissue of secretion,' it being supposed to 

 be secreted by the surrounding epithelia. In verte- 

 brates an anhistic layer in the cornea precedes the 

 true connective tissue (Kessler, Emery). In the 

 embryos of teleosts, particularly those that leave 

 the egg early, the ectoderm is separated by a thick 

 layer of homogeneous, unorganized matter from the 

 inner tissues. This hyaline mass also fills out the 

 embryonic median fins. It is probably changed later 

 into connective tissue by the immigration of cells. 

 The clear membranes separating two adjacent epithe- 

 lia, or an epithelium from connective tissue, the 

 vitreous humor, and the substance filling the segmen- 

 tation cavity of the ovum, are also, perhaps, to be 

 enumerated here as preservations of a very ancient 

 primitive formation, — the tissue of secretion of the 

 most distant ancestors of vertebrates. Its excessive 

 development in teleost larvae is probably an acquired 

 embryonic characteristic. This interesting little pa- 

 per especially deserves attention from those studying 

 the embryology of fishes. — (^rcA. ital. biol., iii. 37.) 



C. S. M. [161 



Fish. 



Motor-nerve endings. — Ciaceio has investigated 

 the motor-nerve plates in the depressor muscle of the 

 jaw of Torpedo marmorata by treatment with double 

 chloride of gold and cadmium. Prom the anterior 

 third of the muscles, strips one millimetre thick 

 were cut with scissors ; the strips were then left for 

 five minutes in fresh filtered lemon-juice, washed in 

 distilled water, and placed for half an hour in a one- 

 per-cent solution of gold and cadmium, being kept 

 dark; washed again in one-per-cent aqueous solution 

 of formic acid, in which they were left twelve hours in 

 the dark, then twelve in the light; finally, kept in the 

 dark in stronger formic acid for one day, and pre- 

 served in glycerine. Such strips may be easily dis- 

 sociated into fibres. 



Two forms of nerve-endings are observed. One, 

 the rarer, represents probably the initial form : it con- 

 sists of bunches of grains, suspended by peduncles 

 arising by repeated division of the pale fibres towards 

 their termination. The second form has been pre- 

 viously described (Mem. accad. sc. istit. Bologna, 



1877), but the following new points deserve mention: 

 the end-plate appears to be more closely united to the 

 sarcolemma than to the muscular substance ; between 

 the ramifications of the fibres appear certain corpus- 

 cles, probably connective tissue, but whether tbey 

 lie within or without the sarcolemma was not deter- 

 mined ; a secondary sheath extends over the primary 

 and secondary, but stops at the tertiary branches; 

 the ultimate terminations are bunches of peduncu- 

 lated grains, the grains being colored dark, their 

 stalks light; finally, the presence of a granular em- 

 bedding substance around the nervous branches. — 

 {Arch. ital. biol., iii. 75.) c. s. m. [162 



Fishes of the Batstoe River, NeTV Jersey. — 

 Professor E. D. Cope stated that eleven species col- 

 lected in the confined waters of a broken dam on the 

 Batstoe River, Xew Jersey, represented the fish fauna 

 of the Carolinian district of the nearctic realm, only 

 three extending into the Alleghanian district. A 

 species of Amiurus new to science was at first sup- 

 posed to be an unusually dark-colored example of the 

 common Amiurus nebulosus. A critical examina- 

 tion soon showed that it differs in the important 

 characters of the considerably more anterior position 

 of the dorsal fin, four to seven more anal radii, and 

 more rounded outline of the caudal fin. Its charac- 

 ters ally it to the western A. natalis, from which it 

 differs by its more slender form and more rounded 

 caudal fin. The name A. prosthistius was proposed 

 for it. — {Acad. nat. sc. Philad.; meeting June 26.) 



[163 

 Uammals. 



Color-markings of mammals. — Professor Elmer 

 has continued his studies in regard to the color-mark- 

 ings of vertebrates. 



As the result of his observations, he has drawn out 

 certain general principles, which he applies to the 

 different groups, notably to the mammals. 



The following general statements are elaborated: 

 1. That the color-markings of mammals may be re- 

 duced to longitudinal stripes, spots, and transverse 

 stripes; 2. That the longitudinal stripes are the old- 

 est form, and that the other two follow in course; 

 3. That the primitive mammalian fauna was a lon- 

 gitudinally striped one; 4. That the males have been 

 first to take on the new forms of markings, while 

 the females hold longer to the older form; 5. That 

 the effects of the law by which the development of the 

 markings takes place from the posterior part of the 

 body toward the anterior part are not so easily traced 

 in mammals as in the case of other groups, such 

 as the saurians; 6. That in mammals the develop- 

 ment of markings follows a regular course, that is, 

 the longitudinal markings are followed by spots, 

 which, in turn, run together, and finally form the 

 transverse or tiger stripes; 7. That the position of 

 the smallest spot on a mammal is not accidental, but 

 due to the action of genetic and philogenetic laws, 

 from which it follows that markings are an available 

 means for the determination of species ; 8. That the 

 regularity of the development of markings shows 

 that they arise from constitutional causes. 



The author takes the Viverridae as the original 



