June 1, 1SS3.] 



SCIENCE. 



493 



division is, however, isolated, and does not cover other 

 parts. In Clepsine this free part consists only of a 

 single row of cells joined like beads on a string. 

 The essential peculiarity of these organs is in the 

 perforated gland-cells, of which there are two forms. 

 The simpler form is found in the middle portion of 

 the organ. Each cell is perforated by a lumen, 

 which communicates and is continuous with the lu- 

 men of the next cell, so that a single string of cells 

 forms a continuous canal. A more complicated form 

 exists in the middle division, in that the cells are per- 

 forated by branching canals, which are continuous 

 from cell to cell. Between these extremes certain in- 

 termediate forms have been observed. — (Arch. mikr. 

 anat., xxii. 78.) c. s. m. [999 



Pilidium larva. — In the last issue of Studies 

 from the biological laboratory of the Johns Hopkins 

 university, E. B. Wilson describes the pilidium larva 

 of a nemertine. It is helmet-shaped, with the con- 

 vex side more elevated than usual, and crowned by a 

 small flagellum. The anterior margin of the bell is 

 prolonged into four short arms, behind which is a 

 deep sinus, followed by two arms on each side, the 

 anterior largest of all. The young nemertines are 

 developed in a folded position within tlie lower and 

 posterior part of the larval envelope, and are dis- 

 tinctly segmented posteriorly. — [Amer. nat., Jan.) 



C. S. M. [1000 



VBRTEBBATES. 

 Direct action of alcohol on the heart. — A 



paper on the above subject was read by Prof. H. 

 Newell Martin, based on researches carried out by 

 him in conjunction with Mr. L. T. Stevens. The 

 experiments were made on the hearts of dogs, com- 

 IDletely isolated from all the rest of the body but the 

 lungs. The pulmonary circuit was intact ; but only 

 the coronary system of the heart was left of the 

 systemic circulation. The rest of the greater circula- 

 tion was carried on through an artificial arterial and 

 venous system. The heart was uniformly supplied 

 with defibrinated dog's blood. The authors found, 1°. 

 That when the blood supplied to the heart contained 

 by volume j of 1 % of absolute alcohol nearly always, 

 and when it contained -J of 1 % invariably, the work 

 done by tlie left ventricle, as measured by the quan- 

 tity of blood pumped out in a minute against a 

 given resistance, was greatly diminished. 2°. If the 

 alcoholized blood were not supplied too long the 

 heart could be restored by feeding it with pure blood. 

 3°. The diminution of work was due to an altera- 

 tion in the physical proijerties of the cardiac muscle, 

 in consequence of which the organ expanded greatly. 

 At the height of its systole it almost completely filled 

 the pericardium, and during diastole had no room 

 to expand and take in more blood : hence it had little 

 or none to pump out at the next systole. 4°. The 

 contractile poM'er of the ventricle is not at first af- 

 fected, since, if the pericardium be cut away so as to 

 give the dilated heart plenty of room for its expan- 

 sion, as much blood is pumped around as if no alco- 

 hol were administered. If, however, the alcoholized 

 blood be supplied to the heart for a considerable 

 time, as ten or fifteen minutes, the muscular power 

 of the ventricle is diminished. .5°. Alcohol in the 

 above-named proportions does not affect tlie rate of 

 beat of the isolated heart. 6°. An experiment made 

 on a total abstainer to whom half an ounce of abso- 

 lute alcohol, diluted with water, was administered, 

 showed that the drug had no influence on the pulse 

 rate, although the dose was sufficient to cause dizzi- 

 ness in the person experimented upon. — (Med. 

 bhirurg. faculty Maryland ; meeting April 20. ) [1001 



Iiingual glands of the frog during secretion. — 



The important discovery of Heidenhain, that the 

 cells of the submaxillary glands undergo visible 

 changes during their secretory activity, has led to 

 numerous investigations on other glands. Among 

 these is Biedermann's research on the lingual glands 

 of frogs. From his prolix and inchoate article we 

 extract the following conclusions : the glands are 

 closely related to the mucous salivaries in character. 

 They are follicular, with their lower ends dilated. 

 The gland-cells have an outer nucleated zone, and an 

 inner granular zone : the former, after the cells are 

 hardened, is stained dark by carmine; in the inner 

 zone, reagents cause the granules to swell, so that the 

 zone becomes hyaline, and, as it does not stain, in sec- 

 tions it appears clear. To call forth the secretion, the 

 glosso-pharyngeus of one side was irritated for from 

 three to five hours ; the tongue was then hardened in 

 absolute alcohol ; and, in transverse section, the resting 

 glands were seen on one side, the active ones on the 

 other. During secretion the granules are poured 

 forth, and probably converted into mucin ; for they are 

 not mucin wliile in situ, because logwood does not 

 stain them. In consequence of the exit of the gran- 

 ules, the cells become narrower (but retain their 

 height), so that the glands are smaller. In the inner 

 zone there is visible only a granvilar protoplasm, the 

 intercellular walls are less distinct, and the so-called 

 'stiitzzellen ' can no longer be well seen. No evidence 

 was had to show that there was a production of new 

 cells during secretion, such as Heidenhain has main- 

 tained occurs in other glands ; nor do any of the cells 

 appear to be destroyed. — {Sitz.-ber. akad. wiss. Wien, 

 Ixxxvi. ill. 67. ) c. s. m. [1002 



Maturation and segmentation of the reptilian 

 ovum. — C. F. Sarasia gives a preliminary notice of 

 his researches on this subject. The most important 

 point is the method of development of the yolk ele- 

 ments out of fine granules, and the continuation 

 of this process during segmentation. The destiny of 

 the nucleus was not satisfactorily ascertained, for the 

 nucleus 'disappeared.' The segmentation differs 

 from what has been hitherto observed in meroblas- 

 tic vertebrates. — [Biol. centralbl.,u\..10B.) c. s. m. 



[1003 



{Man.) 



The lines on the human skin. — The skin is 

 covered by countless fine furrows. Lewinski has 

 studied these, and arrived at the conclusion that 

 they are bends (knlckungen) produced by the move- 

 ment of the skin, either over the joints, as at the 

 knuckles, or directly by the muscles. When the cutis 

 is contracted, the epidermis is laid into folds, which 

 disappear again when the skin is stretclied: so, as 

 the cutis is stretched in the living skin with its nat- 

 ural attachments, when a piece of skin is cut out, it 

 contracts, and the epidermis is thrown into folds. — 

 (Virchow' s arch., ■s.cii.lHo.) c. s. M. [1004 



Sebaceous glands of the tongue. — Ostmann 

 has counted the sebaceous glands at the root of the 

 tongue in man, and finds tliat the range in number 

 is about the same in children and in adults, and that 

 they do not increase very much in number with 

 age, and consequently, as the tongue grows, there 

 are fewer and fewer to the square centimetre. In 

 adults the number varied from thirty-four to a hun- 

 dred and two: the average is sixty-six. In young 

 children the number varied from seventy-four to ' 

 twenty-eight; average, fifty. — ( Virchow's arch., xcii. 

 119.) C. S. M. [1005 



