Fbbbuaby 16, 18S3.] 



SCIENCE. 



53 



world vultures, the former being a group of the 

 Galoonidae. — J. A. j. [157 



Lymph-hearts in the embryo chick. — Frora 

 the observations of Panizza, Meyer, and Stannius 

 {Mailer's arch., 1843, 452), it is known that lymph- 

 hearts occur in various birds, but they have not 

 hitherto been observed in gallinaceous forms. In 

 structure they vary from a rudimentary to a func- 

 tionally perfect condition. These facts lead Dr. 

 Albrecht Budge to consider it probable that they 

 are always developed, and when, absent in the adult, 

 have been atrophied. Upon investigation he suc- 

 ceeded in finding them in the embryo chick. He was 

 successful in injecting the lymphatics in embryos 

 from ten days old upwards. There are two hearts 

 on the back, between the coccyx and pelvis. They 

 enlarge until the time of hatching, after which they 

 both disappear, although one is frequently lost sooner. 

 Small vessels connect them with the vena hypogas- 

 trica on the one hand, and with the lymphatics, es- 

 pecially of the allantois, on the other. The heart is 

 lined with an endothelium, and its wall is composed 

 of connective tissue and spindle-shaped muscle cells. 

 The organ pulsates independently of the blood-pulse, 

 under favorable circumstances, sixteen times a min- 

 ute : the pulsations could be first seen on the eighth 

 day. The dissecting out of these hearts is difficult, 

 as soon after the twelfth day they become covered by 

 fat. — {Arch. anat. physioL, anat. abth., 1882, 350.) 

 c. s. M. [158 



Mammals, ^ 



Fossil peccary from New York. — Dr. Jos. 

 Leidy described two skulls and several portions of the 

 skeleton of a fossil peccary from New York. The re- 

 mains belong to Platygonus compressus, and were in a 

 state of such remarkable preservation as to appear re- 

 cent. — (4cad.7iai.sc. Philad. ; nueting Jau. 2S.) [159 



The phylogeny of the Sirenia, — Prof. E. D. 

 Cope described a portion of the jaw of a large sire- 

 nian mammal, containing an incisor tooth or tusk, 

 characteristic of the genus Halitherium. The speci- 

 men was from the vicinity of Charleston, S.C. It 

 exhibits the peculiarity of possessing, exterior to the 

 tusk, a second large tooth, which is xarobably also an 

 incisoi'. This character was believed to distinguish 

 the form generically from the other members of the 

 order, and the name Dioplotherium was proposed for 

 the genus thus defined. The species was named D. 

 Manigaulti; and, from the proportions of tlie parts 

 preserved, it was believed to have been rather larger 

 than a dugong. 



The genus furnishes a first step in tracing back- 

 wards the phylogeny of the Sirenia. These animals 

 doubtless present the same phenomenon ^s that wit- 

 nessed in the lines of the rhinoceroses, ruminants, 

 and some others; viz., — a gradual reduction in num- 

 ber, and final extinction, of the superior incisor 

 teeth. In Ehytina the extinction is complete; in 

 Halicore, one remains. Dioplotherium, with two, 

 forms the passage to the primitive types, not yet 

 known, which possessed three. They are considera- 

 bly specialized in the present genus, and a reduction of 

 size is to be looked for in the first genera of the Sirenia. 

 — {Acad. nat. sc. Philad.; meeting Feb. 5.) [160 



Synovial membranes. — A monograph of their 

 development and structure, by Oscar Hagen-Torn, has 

 just appeared. A fissure arises by the degeneration 

 of cells between the cartilages. The surrounding 

 connective tissue with many but not essential changes 

 from the embryonic cellular condition of the neigh- 

 boring mesoderm becomes the synovial membrane. 

 The enlargement of the fissure is attributed to move- 



ments of the joints. In extra-uterine life the syno- 

 vialis disappears at the points of great pressure, 

 is thinned out where there is a medium pressure, 

 and acquires the papillose character on the other 

 parts, which are especially exposed to the influence 

 of the negative pressure which arises during the 

 articular movements. — {Arch, niikr. anat., xxi. 591. ) 



C. S. M. [161 



Embryology of the milk-glands. — G. Rein 

 summarizes the results of his extended researches 

 on the development of the milk-glands. The same 

 type of formation was found in all the species in- 

 vestigated. Gegenbaur has maintained, that the 

 majority of mammals have their teats formed by an 

 upgrowth of the area in which the lactic glands are 

 developed; but that in ruminants there is another 

 type, the glandular area forming a depression, the 

 walls of which grow up around it into a teat. Rein, 

 however, demonstrates that the ruminants conform 

 to the usual development. His investigations may 

 be summarized as follows: The first trace of the 

 milk-gland appears very early, usually when the vis- 

 ceral clefts are closed; in man, during the second 

 month. The gland first appears as an ingrowth of 

 the epidermis. The connective tissue of the nipple 

 is next formed; the teat may be developed early 

 (ruminants, horse, etc.), or at the end of foetal life 

 (man). Next secondary outgrowths arise from the 

 primitive epidermal bud, as many as there are ducts 

 in the adults. At this period the differentiation of 

 the stroma from the mesoderm begins. Most of the 

 primitive ingrowth disappears, a little remaining as 

 the common orificial duct. The secondary epithe- 

 lial growths, on the other hand, grow farther, become 

 tubular, branch, and finally form the ducts (sinus 

 and ducts proper) and the acini. In the human foe- 

 tus all the parts of glands are developed by the time 

 of birth. The development is according to this same 

 plan in all the animals investigated, comprising spe- 

 cies of Primates, Insectivora, Carnivora, Ungulata, 

 Glires, and Didelphyda. The so-called Montgomery 

 glands are rudimentary milk-glands. The view ad- 

 vanced by Creighton and Talma, that the acini are 

 developed from the mesoderm, is incorrect. The 

 milk-glands cannot be regarded as modified seba- 

 ceous glands, but are organs sui generis. — {Arch, 

 mikr. anat., xxi. 678.) c. s. m. [162 



Distribution of the genus Macroscelides. — 

 According to M. J. Huet, this genus, as now known, 

 ranges over all Africa, except the western portion 

 between the tropics of Cancer and Capricorn. — {Mis- 

 sion G. Bevoil auxpays QomaUs.) p. w. t. [163 



Anatomical and external characters of Zalo- 

 phus gillespii. — W. A. Forbes i^ublislies two chromo- 

 lithographs of the exterior of the Californian sea- 

 lion, and the following notes together with others: 

 No true scrotum; four inguinal mammae; no under 

 fur; tongue bifid at the apex; stomach less globu- 

 lar and more elongated than in Otaria jubata; intes- 

 tines much longer, and liver less differentiated, than 

 in the latter species; an innominate gives off right 

 and left carotids close together; trachea very wide; 

 spleen flattened and elongated; kidneys compound. 

 The color of the fur is described at length, and meas- 

 urements are given. The full-length figures in the 

 first plate strike one as being unnaturally stiff. — 

 (Trans, zobl. soc. Lond., xi. 18S2.) F. w. T. [164 



Mammals of Essex Co., England. — Notes by H. 

 Laver ujion forty species, including seven cetaceans 

 and the seals Phoca vitulina and Cystophora cris- 

 tata. — ( Trans. Epping Forest nat. club, il. 1882, 157. ) 



F. W. T. [165 



