SCIENCE. 



125 



Ental, and ectal are here first proposed as substi- 

 tutes for the more or less ambiguous words inner and 

 outer, interior and exterior, deep and superficial, pro- 

 found and sublime. Derived respectively from tvr6g and 

 t/crof their significance is obvious, while their brevity and 

 capacity for inflection will probably commend them to ac- 

 curate working anatomists. 



DESIGNATION OF THE REGIONS OF THE LIMBS. 



Barclay's terms ulnar, radial, tibial and fibular refer to 

 only two of the four aspects of each limb. Prof. Huxley 

 has made the very important suggestion that, for compari- 

 son, all vertebrate limbs be regarded as placed in a uni- 

 form normal position ; they are then extended laterad at 

 right angles with the meson, with the convexities of the 

 knee and elbow directed dorsad. Each limb then presents 

 not only a proximal and a distal portion, but four general 

 aspects, dorsal, ventral, cephalic, and caudal. Hence 

 there appears to be no need for the introduction of the 

 new terms employed to some extent by Huxley and other 

 English anatomists, epaxial, hypaxial, preaxial, and 

 postaxial. These words are also liable to misconception 

 because axial has been used already in reference to not 

 only the axis vertebra, but also the entire skeleton of the 

 trunk as contradistinguished from that of the limbs. 



DESIGNATION OF CURVATURES. 



Ordinary descriptions of the directions of curvatures are 

 apt to be ambiguous, and Huxley resorts to the phrase 

 " arcuated outwards " to indicate the form of the mandi- 

 bular rami of the Balaenoidea. Since the Latins designated 

 the two malformations of the legs, " knock-knee " and 

 " bow-legs," by the words varus and valgus respectively, 

 we may find it convenient to speak of parts whose con- 

 vexities look mesiad as varate, and of those whose con- 

 vexities look laterad as valgatef In other cases, how- 

 ever, and perhaps even in these, so long as there is any 

 opportunity for misapprehension, it will be well to describe 

 curvatures as presenting a convexity in one or another 

 direction. For instance, the mandibular rami of the Bal- 

 aenoidea present a laterad convexity, while those of the 

 Physeteridas are convex toward the meson. 



HYPOCAMPA. 



This is employed by Vicq D'Azyr in the descriptions of 

 the plates of his Traite D'Anatomie, published in 1786. 

 The more common form hippocampus occurs in the list 

 of anatomical terms in the same volume, but this may 

 have been compiled partly by others, while the descrip- 

 tions are obviously the work of the anatomist himself. 

 Vicq D'Azyr does not discuss the etymology of the term, 

 but says the " grande hypocampe " was first mentioned by 

 Arantius and Varolius, whose works are not now accessi- 

 ble to me. Even Hyrtl does not seem aware of the use 

 of the word by Vicq D'Azyr, and all other writers, so far 

 as I know, make it hippocampus. 



If the original orthography cannot be ascertained, hy- 

 pocampa is to be preferred on etymological grounds ; 

 the ridges known as hippocampus major and h. minor 

 bear no obvious resemblance to the fish known to the 

 ancients as inTrom/moc and hippocampus, but the larger 

 of the two, which probably first received the name, does 

 certainly present a most notable downward curvature, 

 such as the Creeks might have designated by in-oKa/iK//, 



DESIGNATION OF THE ENCEPHALIC CAVITIES. 



As based upon the condition of things in man the cur- 

 rent nomenclature of the ventricles had some slight 

 foundation. But, in the light of better methods and more 

 accurate knowledge, it appears incongruous and need- 

 lessly perplexing. 



Let the learned anatomist lay aside his familiar ac- 

 quaintance with the parts and their names, and put him- 

 self in the place of the beginner who, after gaining a gen- 

 eral idea of the arrangement of the vertebrate brain from a 



frog or menobranchus, is trying to master the complexi- 

 ties of the mammalian organ from the brain of the cat, 

 dog or sheep. 



Leaving the myelon, he finds the canalis centralis ex- 

 panding into a cavity which, although the first of the se- 

 ries, is called the fourth ventricle. The more or less 

 distinct cavities corresponding to the cerebellum and the 

 lobi optici are not called ventricles at all, and the third 

 is between the thalami. The two " lateral " ventricles 

 are rarely mentioned as the first and second, but since the 

 numbers must be understood in order to account for the 

 third and fourth, the student desires, in vain, to know 

 which is the first and which the second. In point of 

 fact, if the enumeration is begun at the cephalic end of 

 the series, the lateral ventricles are the third and fourth, 

 since there are well-developed ventricles in the lobi ol- 

 factorii. Finally, a "fifth ventricle" is mentioned, which 

 is not only at the greatest distance from the fourth, but 

 has no normal connection with the other ventricles, and 

 is, in fact, no part of the series. 



in view of all this, the task of describing to students 

 the highways and by-ways of the brain, — which should 

 be most attractive because therein is most clearly mani- 

 fested the ideal arrangement of the organ, — is one from 

 which I shrink as from any other kind of solemn non- 

 sense. To my mind, indeed, rather than go on as we 

 have been going, it would be at once more philosophical 

 and more intelligible to adopt the simple vocal device 

 employed by Straus-Durckheim for the designation of 

 the metatarsalia — " padion, pedion, pidion, podion, pu- 

 dion " — and to re-christen the ventricles by, for instance, 

 the names pran, pren, prin, pron, and prun. 



Fortunately, however, another alternative is presented. 

 Whatever objections may be urged against them on 

 theoretical grounds, a real practical advantage is gained 

 by ihe use of the terms rlunencephalon, prosencephalon, 

 aiencephalon, mesencephalon, epencephalon, and meten- 

 ccphalon, and their German or English equivalents are 

 likewise often employed for the designation of the gen- 

 eral regions of the brain. Assuming that these terms 

 are to be retained, and that they are to be learned by 

 successive generations of students, why should we not 

 transfer the distinctive prefixes to the Greek word for 

 ventricle, ccelia, KotMa ? This would give us rhinocoslia, 

 procailia, dic&lia, mesoc&ha, epiccelia, and metacalia. 



These terms are capable of inflection, and the longest 

 of them is no longer than the Latin ventriculus, which 

 requires a prefix or qualifying word. Lastly, but by no 

 means of least importance, they correspond with the 

 names of the encephalic segments. As will be seen in 

 the list of names of the parts of the brain, these pre- 

 fixes are employed for the designation of the mem- 

 braneous roofs of the "third" and "fourth" ventricles, 

 and the plexuses of these and the lateral ventricles. 

 After a somewhat prolonged consideration of the mat- 

 ter, it seems to me that the practical uselulness and 

 logical consistency of these new terms outweigh any 

 objections that may be urged, and that these latter are 

 less numerous and serious than could be brought against 

 any other substitutes for the present heterogeneous and 

 ill-applied nomenclature. 



Two or more ventricles may be spoken of as ccehce, 

 while the " fifth " may be called pseudo ccelia. I hope, 

 before long, to justify more fully the proposition already 

 made* to consider the cephalic portion of the " third " 

 between the.portc? (foramina Monroi), as a morphologi- 

 cally independent cavity under the name of aula. 



RHINEN, ETC. 



May not rhinen., prosen., dien., mesen. and epen. be 

 written, for the sake of brevity, for the full titles of the 

 general divisions of the brain, rhinencephalon, prosen- 

 cephalon, etc ? 



* Proceedings of the Am. Assoc. for Adv. of Science, Aug. 25, 1880 

 reported in " New York Medical Record." 



