HARDWICKE'S SCIENCE-GOSSIP. 



257 



burlesque on the doctrine, we think it would have 

 achieved its end much better. Whether Evolution 

 be true or false, it is certain that the question is of 

 too serious a nature to be so flippantly disposed of 

 as Dr. Wood imagines. We want to get at the 

 truth of God's universe, not'to be constantly taking 

 partisan sides in the matter, and ligliting for 

 systems as if they were in the place of great truths. 

 We therefore deplore such books as these, as likely 

 to injure the cause they attempt to further. Having 

 delivered ourselves of this opinion, we may remark 

 that the book is well written, and displays a know- 

 ledge of the subject we should have been glad to 

 see worked out differently. Every now and then we 

 get an idea or a generalization which shows us 

 that the author could have done so, had he thought 

 fit. 



'■ Half-hours in the Green Lanes " may seem to 

 come late for what notice we ought to give of it. 

 Criticism we leave to others, with due gratitude for 

 such kindly remarks as have already been made 

 concerning it. All we have to do is to anuomice 

 its existence, and to say that the endeavour of the 

 author has been, by its means, to make a country 

 stroll both more enjoyable and more instructive. 



MICROSCOPY. 



BxVCTERiA AND MiCROZTMES. M. Bcchamp and 

 M. Esvor, in a paper published in the " Comptes 

 Rendus," have shown that, in the stomach of a dog 

 during digestion, microzymes are found, and various 

 forms of Bacteria. Beyond the pylorus, nothing 

 but microzymes are met with till the ileo-caical 

 valve is reached. In the large intestine Bacteria 

 are abundant. If, however, there be in the intestine 

 any cause of irritation, such as a tapeworm, micro- 

 zymes are immediately developed into Bacteria. 



Life-History of a Cebco-Monad. — A most 

 important paper, bearing the above title, recently 

 appeared in the Monthly Microscopical Journal from 

 the pen of Messrs. Dallinger and Drysdale. These 

 gentlemen have, with the highest objectives, and 

 the most admirable patience, watched the entire 

 development of the creature above named. They 

 continuously examined, during sometimes as long a 

 period as fourteen days, a peculiar monad, hitherto 

 undescribed, but which is from some circumstance 

 developed in enormous quantities in the fluid 

 resulting from the maceration of the head of a cod. 

 This form passes through a remarkable series of 

 changes, each of which might be taken for a 

 distinct and independent creature, were not its 

 evolution perfectly regular. Whilst observing this 

 object they noticed a second form, which possessed 

 only one flagellum instead of two. When 

 mature, this form multiplies by fission for a period 

 extending from two to eight days. It becomes 



peculiarly amoeboid, two individuals coalesce, slowly 

 increase in size, and become a tightly distended 

 cyst. The cyst bursts, and incalculable hosts 

 of immeasurably' small sporules are poured out as 

 if in a viscid fluid, and densely packed. These 

 are scattered, slowly enlarge, acquire flagella, 

 become active, attain rapidly the parent form, and 

 once more increase by fission. Experiments were 

 next made to determine the influence of heat. An 

 ordinary slide, containing adult forms and sporules 

 covered in the ordinary way, was in seven distinct 

 cases allowed to evaporate slowly, and placed in 

 a dry heat raised to 250^ E. It was then slowly 

 cooled, and distilled water was taken up by capillary 

 attraction. On examination, all the adult forms 

 were seen to be absolutely destroyed, and no spore 

 could be definitely identified. After being kept 

 moist in the growing stage for some hours, and 

 watched with the Toth, gelatinous points were seen 

 in two out of the seven cases, which were recog- 

 nized as exactly like an early stage of the develop- 

 ing sporule, and by careful watching, these were 

 observed to attain the small flagellate state. 



EocAL Differences of the Eyes. — I have just 

 had a fact communicated tome relative to the above 

 subject, which might prove of interest to Science- 

 Gossip. A gentleman (who is a student of the 

 microscope) informed me that he always found a 

 difliculty in studying with a binocular microscope, 

 in that he could never get the two glasses to blend. 

 In 1851 he went to the Great Exhibition, where the 

 eye was constantly ranging from short to long dis- 

 tances. After he had left the Exhibition he felt 

 that his eyes were very much fatigued, and was at 

 a loss to understand the meaning of it. By this and 

 other circumstances he discovered that there was a 

 focal dijference in his eyes. That one eye was far- 

 sighted, while the other was «mr-sighted. He 

 showed me a pair of spectacles he wears for reading 

 purposes, in which the one glass is made for the/«r 

 sight, while the other is a plain glass, the left eye 

 being «mr-sighted, and consequently requiring no 

 aid from spectacles with which to read. Since this 

 was told me I have heard of two other instances 

 where people were observed always to read with one 

 eye. Probably they could not have told the reason. 

 This may possibly be the case with other people, 

 while all the time they are in utter ignorance of it. 

 Thus in the literal sense of the words we may be 

 blind without knowing it. If any should be under 

 an apprehension that they have this defect, the way 

 to prove it is simple enough. Hold up a piece of 

 card before one eye, and then look at an object before 

 you. Then gradually bring the card across to the 

 other eye, and see if your view is as perfect ; if so 

 your eyes are perfect as regards the balance of their 

 foci. If not, there is a focal difference, more or 

 less decided. Doubtless this will account for some 



