THE MICROSCOPE. 113 



buy a microscope, first of all send to each of our advertisers for a 

 catalogue and price list, then study which style you prefer, and when 

 you have decided with which house you wish to deal, if you choose, 

 you may make your order through us, and we will give you the in- 

 strument at the same rate the dealer will, that is, we will give you 

 our experience in buying. In no case will we order from a house 

 who does not advertise with us, and in every case will we order from 

 the house you choose. Again, in no case will we choose the house 

 for you, and, in every case, having chosen your dealer, as Grunow, 

 Pike, Reynolds, etc., will we advise with you as to the best instru- 

 ment they offer for your particular wants and for your means. 



DR. P. Grawitz in "Arch. Path. Anat. Physiol. (Virchow), vol. xxxii, 

 (1880) pp. 355 — 376" has shown a remarkable similarity, in all 

 essential points, between the dermatophytes which accompany 

 different infections diseases, and the milk-ferment, oidium lactis, 

 making them almost identical. 



The two most widely distributed and best known of the fungi 

 in question, aspcrgillus glaiicus (the mould found generally on canned 

 fruit and preserves) zxi^ penicilUnm glauciim (the growth on mouldy 

 bread) each occur in two different forms which present no morpholog- 

 ical difference, but which differ very widely in their physiological 

 properties. The one (saprophytic) may be introduced into the blood 

 of the higher animals without showing any disposition to germinate; 

 the other (parasitic) germinates and spreads with the greatest facil- 

 ity. Both forms may be produced from the same original item, and 

 each form may be reproduced through from twelve to twenty gener- 

 ations, and may then give birth to the other. The malignity of the 

 parasite depends on the entrance of the spores into the the blood, 

 when they germinate, and then pass with great rapidity into the 

 various tissues of the body, where they cause local necrosis. 



IT is impossible to predict, at this time, some of the wonderful 

 things that will develop fromDr. Hahn's discovery of fossil organ- 

 isms in meteorites. It has started a lively discussion, and we await 

 with intetest the outcome of the matter. A large number of scien- 



