Microscope Teachings. 429 



get at them : I take the little scrap of skin and tear it in two, 

 exactly as if I were splitting a card, for the skin consists of two 

 layers. I can easily lift them off with a knife and mount them 

 for the microscope, while the skin makes another very pretty 

 object for it, not unlike the spotted coat of a leopard." 



Mrs. Ward's sixth chapter is devoted to hah- and feathers ; 

 and, like the preceding, is beautifully illustrated ; the seventh, 

 relating to " eyes and other objects," also furnishes materials for 

 an instructive plate, and shows how the optical apparatus of 

 fishes, insects, and other accessible creatures, must be treated 

 in order to display their elaborate provisions and adaptations 

 to the conditions under which then owners live. The eighth 

 chapter treats of "vegetable productions," the ninth of 

 "organic remains, crystals, and artificial objects; the tenth 

 and eleventh discourses of animalcules, and the twelfth con- 

 cludes the work with an excellent little essay on " the circula- 

 tion of the blood," and the various ways in which it may be 

 pleasantly observed without injury or pain to the animal 

 employed. The phenomena of circulation may be well shown 

 in the young water newt, easily obtained from ponds in the 

 spring. Mrs. Ward observes concerning it: — "The young- 

 smooth newt retains its external branchiae to a much later 

 period than is the case with the frog tadpole ; although it would 

 seem, from what I have observed, and also from Professor 

 BelPs remarks on this subject, that there is a great variety in 

 the period at which the branchiae disappear in this species. 

 I have, however, constantly met these young newts, when 

 nearly two inches in length, still possessing those beautiful ap- 

 pendages ; which, instead of being pale as at first, appear of a 

 fine chestnut colour ; but they have lost much of their trans- 

 parency, and therefore for microscopic observation the newts 

 answer best when of the size represented in the figure, and till 

 they have grown to about twice that length. The great size of 

 the corpuscles, as compared with the size of the animal, makes 

 the object exceedingly striking. They are oval, like those of the 

 frog, but larger, being (in round numbers) one eight-hundredth 

 of an inch in length, while those of the frog are one eleven- 

 hundredth ; and both these are singularly large compared with 

 those of man; these latter are but one three thousand two- 

 hundredths of an inch in diameter." 



Mrs. Ward also states that little newts are more tractable 

 than frog tadpoles, and consequently easier to see ; she likewise 

 recounts how she once noticed the appearance of " a pink spot, 

 apparently fading and re-appearing a number of times in a 

 minute." This was the little creature's heart propelling its in- 

 fant stream. 



The specimens we have given will show the clearness of 



