1882.] 



MICKOSCOPICAL JOURNAL. 



233 



place a drop or two of turpentine, 

 which we then shake out again, and 

 fill up the cell with the fluid balsam. 

 Into this we place the object, taking 

 it from the turpentine in which it had 

 been left to soak, and arranging it in 

 the cell. On the under surface of a 

 clean cover-glass we place another 

 drop of turpentine, allow it to run 

 off, and then lower down the cover- 

 glass just as in the former case. 

 After the spring-clip has been on 

 for a day or two, we can carefully 

 scrape off the excess of balsam, wip- 

 ing the top carefully with a rag mois- 

 tened in spirit, and then running a 

 ring of cement round the edge as 

 before. 



And now we have mounted, let us 

 say two heads of the blow-fly, — one 

 in glycerin fluid, the other in Ca- 

 nada balsam. Let us see how they 

 look through the microscope. Our 

 first impression is — how different the 

 object appears to that spread-eagle 

 thing we have so often looked at ! 

 Why, we can actually focus down and 

 see, first, the tips of the hairs on the 

 fly's head ; then we see their inser- 

 tion on the scalp ; and focussing 

 somwhat lower we enter the cavity 

 where once part of the brains were, 

 — only a cavity now, through which 

 meander a pair of tracheal tubes, but 

 where once our blow-fly did all her 

 thinking, — where she laid her plans 

 for stealing our sugar, and for the 

 safe depositing of those minute pro- 

 geny so dear to the cultivators of 

 the gentle angling craft. Lower down 

 still we come to the roots of the 

 hairs at the base of the skull. We 

 really must have revolved our fine 

 adjustment- wheel some dozen times, 

 and we remember how formerly, with 

 only half a turn, we used to find 

 ourselves at the other side of our 

 flattened specimen. 



On each side of the globular head 

 stand out the many-facetted eyes. 

 At the base of the proboscis which 

 juts out from the front are the 

 strange pair of antennae. In the 

 middle of the proboscis stand out 



the palpi. In a groove near its end 

 lie the sharp setae or lancets. The 

 end is swelled out by a beautiful 

 network of pseudo-tracheae into two 

 semi-heart-shaped masses, between 

 which we discern the salivary tube. 

 And now it is easy to understand 

 how the sugar disappears. There, 

 under our binocular, the tongue 

 of a blow-fly stands out solid, and 

 looks as we never saw it before ; it 

 is more than ever a thing of beauty, 

 but its use also is plain. Turning 

 over the slide, we notice underneath 

 the narrow opening from which some 

 tracheae still project, and through 

 which there once passed nerves, 

 muscles, digestive canal, and tracheae, 

 from the head to the body. 



Let us henceforth resolve that we 

 will no longer crush out of their 

 real semblance any more of nature's 

 beauties, no longer fill our minds 

 with false notions of the truth; but 

 preserve, so far as we can, the true 

 and lovely form that nature every- 

 where bestows upon her creatures. 



An Easy Method of Detecting 



Bacillus Tuberculosiis for 



Diagnostic Purposes.* 



BY GEO. A. PIERSOL, M. D. 



* * * At the present time there 

 is, probably, no other subject re- 

 ceiving more earnest study and 

 careful investigation than that of the 

 discoveries of Koch regarding the 

 bacillus of tubercle. While these re- 

 searches bid fair to yield the most 

 important results, it is no disparage- 

 ment to that excellent observer to 

 assert that extended investigation 

 into the modifications naturally re- 

 sulting from the manipulations of dif- 

 ferent workers, will alone develop 

 and complete our knowledge of the 

 conditions of existence and life- 

 history of the micro-organism, and 

 determine the exact value of its pres- 



* Abstract of an article in the Western 

 Medical Reporter. 



