430 



NA TURE 



{March 30, 1876 



most of them are land animals, a few only being in- 

 habitants of fresh water, and one — the genus Ambly- 

 rhynchtis of the Galapagos Archipelago— lives on the sea- 

 shore, and, if hard pressed, takes to the sea. 



Through the whole of the Tertiary epoch the lizards 

 are essentially the same as those now existing. Some of 

 the Secondary species, also, have the same characters, but 

 in the chalk are found, in addition, strange marine lizards, 

 such as the genus Mosasaurus, which attained a length of 

 30 feet. As far back as the Purbecks, the lizards have verte- 

 bras like the existing kinds, but on descending to the Solen- 

 hofen slates we find abundant remains, which present the 

 lower character of bi- concave vertebrae, and the same is 

 true of all the still older forms, such as the Tderpeton of 

 the Triassic sandstones of Elgin and the Permian Proto- 

 rosaurus. 



Thus the older lizards have a slightly simpler structure 

 than those of the present day, but resemble them, on the 

 whole, so closely, that we must conclude our existing 

 forms to have been derived from the ancient ones, and 

 have no need whatever to assume their special creation. 

 Lizards, then, offer another example of what is meant by 

 a persistent type. 



A remarkable instance of this persistence is afforded 

 by a case of quite the same order as that of Ceratodus, 

 described in the first lecture. The Hatteria, mentioned 

 above, differs from all other lizards in many particulars. 

 Its jaws are armed with a horny beak, and its upper jaw 

 has two rows of teeth, one on the maxillary, the other on 

 the palatine bones ; the teeth of the lower jaw bite between 

 these, like a pair of scissors with a double upper blade. 

 The vertebras are bi-concave, and, along the belly, are 

 placed a number of bony plates. 



No other existing form whatever is known presenting 

 these characters, but, about the year 1858, a number of 

 fossils were discovered in the sandstone of Elgin, and 

 amongst them the remains of a large lizard with bi-concave 

 vertebras, abdominal plates, a horny beak, a double row of 

 upper jaw teeth, and, in fact, altogether like the existing 

 Hatteria. 



The crocodiles are the only other reptiles the history of 

 which it will be possible to notice in this course. Two of 

 the most important characters by which they are distin- 

 guished from Hzards are, the lodgment of the teeth in dis- 

 tinct sockets and the position of the hinder nostrils or 

 posterior nares. The maxillary, palatine, and pterygoid 

 bones are so disposed as to form a remarkable shelf or 

 partition in the roof of the mouth, thus bringing the 

 posterior nares to the hindermost part of the throat. 

 The soft palate forms a veil in front of these aper- 

 tures, and hangs down so as to rest on the back part of 

 the rudimentary tongue, and thus, except when the animal 

 is swallowing, entirely shuts off the cavity of the mouth 

 from the air passages. This arrangement has been prettily 

 explained by the crocodile's habit of killing its prey by 

 drowning ; it is said that it can hold a captured animal 

 under water, while its own nostrils — placed at the end of 

 the long snout — are just above the surface, and thus is 

 enabled to breathe freely, the air passing through the 

 posterior nares, behind the veil of the palate, and so to 

 the lungs, while its prey is being suffocated. This is an 

 admirable explanation as far as the crocodile is con- 

 cerned, but, unfortunately, it is probably untrue, for pre- 

 cisely the same arrangement is found in the Gavial and 

 other crocodilians which live upon fish. 



( To he continued. ) 



PHYSICAL SCIENCE IN SCHOOLS 



pROF. ROSCOE has tak.n the right view when he 

 ■*■ says that science teaching in schools will remain 

 unsatisfactory as long as it does not receive the same 

 range and time as the subjects which at the present time 



preponderate so greatly. Granting the necessity of devot- 

 ing more time to science, it follows, almost as a matter of 

 course, that science teaching ought to begin at an earlier 

 age than now. For else, where is the time to come from ? 

 The other alternative — to r.dd a couple of years to the 

 time required to pass through the present curriculum of a 

 public school— would be accepted by very few parents. 

 But there is no need for this alternative. The teaching 

 of the elements of physical and chemical knowledge is 

 most beneficially begun in early years. Some of the fore- 

 most thinkers of the scientific world assert and support 

 this view, as may be gathered, for instance, from the Sixth 

 Report of the Royal Commission on Science Teaching. 

 I would mention, in addition to this, that Liebig strenu- 

 ously advocated ("Chemische Briefe," Leipz. und Heidelb., 

 1865, 50th letter) the teaching of such elementary chemistry 

 in village schools as bears upon the constitution of air, 

 water, the ash of plants, and explains the process of com- 

 bustion. The great German philosopher would hardly 

 have done so, without being sure that the pupils will profit 

 by the teaching. The average age of such a pupil is, I 

 believe, twelve years, and he receives, as far as I am 

 aware, no preparatory instruction in algebra or geometry. 



It is surprising to find a man of the educational 

 eminence of Mr. Wilson battling against early science 

 teaching. I am inclined to ascribe his opinion on this 

 matter to an incomplete view taken by him of the true 

 significance science teaching has. Mr. Wilson considers 

 the study of physical science as a means of developing 

 merely the reasoning faculty of a boy, leaving out of 

 sight the equally important function of calling forth and 

 sharpening the faculty of observation. As for reasoning 

 alone, certainly, the languages, and still more, mathe- 

 matics, afford at least an equally good basis. It is just 

 the circumstance that a sound teaching of science shows 

 to the young mind the difference between evidence as 

 resting (wholly, or to the greatest extent) on the teacher's 

 statement, and evidence based on facts put actually 

 before the pupil, which makes the study of science so 

 valuable from a general educational point of view. 



Early beginning of science teaching suggests itself for 

 yet another reason. Everyone, with but the least experi- 

 ence in educational matters, knows that in order to be 

 successful' in instruction, one must repeatedly go over the 

 same ground during the curriculum of a boy's education, 

 and gradually expand the subject in the repetition. Why, 

 then, shall not science, if it is to enter organically into 

 the education of a boy, and not be merely tacked on to him, 

 receive the same treatment ? Let a boy at the age of ten 

 or eleven begin with witnessing all the experiments which 

 are usually performed in illustrating those sections of Che- 

 mistry and the science of Heat, that are required from the 

 candidates of the London University Matriculation Exami- 

 nation. Let the boy become thoroughly acquainted with 

 the facts, and let at this time as little theory be placed 

 before him as possible. After such a course, which might 

 be made to fill up two years, there should be a pause in 

 the study of these branches of science for a year, or even 

 two, before allowing the pupil to resume the same in a 

 fuller and more theoretical way. The hours gained might 

 be given to mathematics. Of course it would be out of 

 place to give here anything like a programme of how the 

 above idea should be realised ; I must just content myself 

 with throwing out the hint. After the initiatory course 

 the pupil will be in better condition to follow later the 

 theoretical parts than he is under the present system, 

 where he has to overcome simultaneously the novelty of 

 the facts and the difficulties of the theory. 



Science acquired in this way will be very different from 

 that which is hastily got up in the last six or eight months 

 of a boy's stay in the school, and mostly, too, under the 

 pressure and anxiety which accompany the preparation 

 for some examination, say the London University Matri- 

 culation. 



