584 



SCIENCE. 



as to materially affect the temperature of the planets. 

 " This seemed a very reasonable view, and, indeed, it can- 

 not well be questioned that if one-half of the heat that 

 reaches the earth's surface comes from the stars, it is 

 likely to be warmer near an aggregation of three suns 

 than it is where we are now " (p. 70) ; but astronomical 

 considerations show that the hypothesis as a whole is 

 untenable. Next is the view of Lyell, who attributed 

 climatal oscillations to changes to the relative position 

 of sea and land ; but the view is open to the sweeping 

 objection that the formulated cause would produce oppo- 

 site effects from those which the hypothes ; s attempts to 

 explain. The effect, of minor geographical alterations on 

 climate cannot, however be denied. Tyndall and others 

 have shown that slight variations in the quan'ity of 

 aqueous vapor, carbonic acid, or some other substances 

 contained in the atmosphere must materially effect terres- 

 trial temperature ; but any such variations which we are 

 justified in assuming would probably be inadequate to 

 alone explain the phenomena of the glacial period. The 

 next hypothesis is that of Croll, who, recognizing the fact 

 that the " orbit of the earth around the sun is not circu- 

 lar, as it might be if the earth were the only companion 

 of the sun in the solar system " (p . 73), points out (1) 

 that during periods of high eccentricity in the terres- 

 trial orbit the precession of the equinoxes may lead to a 

 considerable variation in the length of the seasons, and 

 hence to an accumulation of snow and ice in the hemis- 

 phere having the long winter and the short summer ; and 

 (2) that when such accumulation was in the northern 

 hemisphere the effect upon the trade winds would be such 

 as to deflect the Gulf Stream feeders to the south of Cape 

 St. Roque and thence into the Antarctic regions, and 

 thus further refrigerate the northern hemisphere. The 

 hypothes ; s is the most important yet enunciated, though 

 it presents certain difficult.es. Other views are that 

 changes in the earth's axis of rotation, or in the obliquity 

 of the ecliptic may materially affect the temperature of 

 the globe ; hut these views can be mathematically proven 

 to be inadequate. Yet another hypothesis is that which 

 attributes the phenomenon to variations in solar emission, 

 and which " seems a most likely cause of glacial condi- 

 tions " (p. 90). Less important hypothetical causes are 

 minor geographical changes affecting aerial or marine 

 currents — for instance, the comparatively recent eleva'ion 

 of Sahara, and the probable late Quaternary depression 

 and subsequent re-elevation of Alaska and Kamchatka ; 

 but it is clear that no conceivable array of geographical 

 changes can explain the origin of the last glacial epoch. 



(To be continued^ 



The Hippopotamus. — Dr. Henry C. Chapman, of Phila- 

 delphia, has recently devoted much attention to the anatomy 

 of the Hippopotamus, and has read an elaborate paper before 

 the Academy of Natural Sciences, of Philadelphia. We 

 notice that he draws the following conclusions: "begin- 

 ning with the pig, we pass by an easy transition to the 

 Piccary, which leads to the Hippopotamus, and thence in 

 diversing lines to the Ruminantia on the one hand and 

 the Manatee on the other. Paleontologists have not discov- 

 ered a form which bridges over the gap between the Hippo- 

 potamus and the Manatee, but it will be remembered that 

 certain fossil bones, considered by Cuvier to have belonged 

 to an extinct species of Hippopotamus, H. Mvdius, are re- 

 garded by Gervais as the remains of the Halithorerium fos- 

 sile, an extinct Sirenean of which order the Manatee is a living 

 representative." Dr. Chapman adds further on, " I do not 

 mean to imply that the Manatee has necessarily descended 

 from the Hippopotamus," but he considers that "there is 

 some generic connection between them." 



Prof. C. V. RlLEY believes that the diminished virulency 

 of Phylloxera in sandy soils is due to its mechanical action 

 on the insect, his own experiments showing the difficulty 

 such insects meet with in soils of a sandy nature. 



NEW YORK ACADEMY OF SCIENCES. 

 Xovember 21, 1881. 



Section of Biology. 

 The President, Dr. J. S. Newberry, in the Chair. 

 Thirty one persons present. 



The following paper was read by Prof. Louis Els- 

 berg, M. D. 



On the Cell-Doctrine and the Bioplasson- 

 Doctrine. 



Mr. President and Fellows of the Academy, Ladies and 

 ■ Gentlemen. — Last May, at the meeting of the American 

 Laryngolcgical Association, I rendered account of some 

 histological investigations of the cartilages of the larynx, 

 j a report of which is published in the October Number of 

 ' the Archives of Laryngology. As the structure of hya- 

 line cartilage has an important bearing on my subject of 

 this evening, I crave your attention for a few minutes for 

 a brief review of those investigations. 



You know the larynx or voice-box consists of a frame- 

 work of cartilage or gristle. This cartilage is called hya- 

 line or glasshke, because it is opalescent and looks like 

 milk-glass. Having frequently been examined under the 

 microscope, it has always been looked upon as one of the 

 simplest tissues, namely, as being composed of a hard 

 matrix or basis-substance, in which are imbedded a num- 

 ber of small softer bodies. These softer bodies, the carti- 

 lage corpuscles, have since the establishment of the cell- 

 doctrine been called cartilage cells. As these cells were 

 known to be alive, the question which scientific men have 

 j had to try to answer was : how can they obtain nutrition, 

 j being isolated and enclosed in the firm, unyielding carti- 

 lage basis-substance? 



Without going too much into details, I may say that it 

 was assumed that nourishing liquid reaches the corpuscle 

 either by imbibition and diffusion or else through canals 

 or fissures in the homogeneous basis-substance. The idea 

 of the existence of " ju ce-channels " originates with VON 

 Recklinghausen, although others before him had 

 spoken of " pores" through which nutrient juices might 

 pass. Budge and others believe in the presence of regu- 

 lar canals for this purpose, while Tillmanns and many 

 with him believe that hyaline basis-substance consists of 

 fine fibrils so closely held together by a cement-substance 

 that the mass appears to be homogeneous ; it is supposed 

 by some that this inter-fibrillar cement-substance is a vis- 

 cous, soft material which permits the imbibition of nutri- 

 ent liquid ; by some that there are clefts or fissures, and by 

 others that there are regular channels tunnelled in this 

 cement-substance. On the other hand, Heitzmann, 

 Spina, Flesch and others have found that there are ci- 

 lia-like offshoots or prolongations of the substance of the 

 corpuscle penetrating into the basis-substance. Such pro- 

 longations might carry on nutrition. I have had the op- 

 portunity 6 or 7 years ago to repeat Heitzmann's observa- 

 tions under his own eyes and with his assistance ; but 

 the results as to their correctness at which I arrived, were 

 to the best of my belief uninfluenced by him. 



My own recent investigations have not only confirmed 

 the existence of such offshoots and shown that they form 

 an inter-connected reticulum or network throughout the 

 basis-substance, but I have discovered in several speci- 

 mens, small lumps in this network which, by all the tests 

 applied to them, were proved to be lumps of living mat- 

 ter in various stages of existence ! These investigations 

 are illustated by the accompanying drawings viz. 



Fig. 1. exhibits the appearance of a longitudinal section 

 of the plate of the thyroid cartilage with an amplification 

 of 100 diam. 



Fig. 2. shows offshoots from the cartilage corpuscles and 

 the network in the basis-substance with more or less large 

 granules interwoven, as it were, in the network. 



