186 BACTERIA IN THE SPUTA 



coloured, in a clear area. This fact is to be attributed to the 

 subsequent action of the colouring matter. 



Besides the bacilli of Koch in rosaries, we have others in small 

 rods or filaments containing granules or vacuoli, as in Fig. i of the 

 work of Cornil and Babes, etc. These rods appear more clearly 

 when stained by Gram's method — viz., with double colouring, first 

 with gentian violet and then with solution of iodine. Now, the 

 fragments and slender stems of Leptothrix, in the patina de?ttarta, 

 behave likewise. If the solution of iodine should be used first, 

 the successive colouring with gentian violet does not succeed; but 

 if we colour with violet, as usual, mounting the preparation when 

 fresh, and then introducing by capillarity the solution of iodine, 

 the violet colouring becomes dark blue and the small rods of 

 Leptothrix appear very clearly. 



On another occasion I shall treat those questions relating to 

 the finding and colouring of the tubercular bacilli. 



Productions by Points (Male Organs ?) 



I have already said that such productions or pseudo inflores- 

 cences are scanty, so that we must seek them patiently in the 

 preparation. They have, however, the advantage of showing 

 themselves clearly, even without colouring. It is absolutely neces- 

 sary to examine the patina dentaria of persons who have fasted 

 and who are not in the habit of cleaning their teeth, otherwise we 

 may not find these productions. The preparation should not be 

 pressed too much, in order to avoid the disintegration of the spe- 

 cimens. They are easily recognised with an objective, No. 8 of 

 Hartnack. The above-mentioned difficulties indicate why such 

 forms have not been considered by previous investigators. 



In Fig. 14 are shown three of these productions in the natural 

 state, taken from the pati?ia dentaria, and magnified to 690 dia- 

 meters. They are formed of one or more internal stocks and a 

 considerable number of points which surround them, like the 

 horsehairs of a cylindrical brush. In a the production rises upon 

 a multiple stalk, formed of a bundle of filaments apparently 

 broken off. The stalk itself is crowded with small points near the 

 trifurcation ; the three small divided branches bear longer points 



