DESCRIPTION OF PLATES. 



PLATE I. 



FIGS. 1 to 9. Cysts of Entamceba Mstolytica from three cases to show how distinct 

 strains occur. 



1 to 3 : Cysts from case Healy, with a strain of E. histolytica producing 

 large cysts. 4 to 6 : Cysts from case Flynn, with cysts of intermediate sizes. 

 7 to 9 : Cysts from case Russell with cysts of small size. The cysts are drawn 

 to the scale below fig. 9. 



FIGS. 10 to 23. Entamceba nana, n. sp. 



10 and 11 : Free forms as seen in fresh preparations. 12 to 17 : Free forms 

 as seen in films fixed in Schaudinn's fluid and stained with iron hsematoxylin. 

 Fig. 15 shows a type of nucleus which is often seen in the encysted forms. 

 18 to 23 : Various stages in the development of the cyst. Forms with one, two, 

 and four nuclei. Fig. 20 shows dividing nuclei. Fig. 22 shows a very charac- 

 teristic type of nucleus, in which a large chromatin mass on one side of the 

 nuclear membrane is connected by a filament to a small granule on the mem- 

 brane opposite to it. The free amoebae measure 5 to 10 microns in diameter, 

 while the cysts are 8 to 10 microns in length. 



PLATE II. 

 FIGS. 1 to 5. Various stages in the longitudinal division of Lamblia intestinalis. 



1 : Division of nuclei. 2 : Form with four nuclei. 3 : Commencing division 

 of bodv. 4 : Final stage of division. 5 : Form with two sucking discs developed. 



FIGS. 6 to 15 : Tetramitus mesnili. 



6 to 9 : Forms showing twisting of the body, a condition very commonly seen. 

 10 to 12 : Encysted forms as seen in fresh preparations. The only contents to 

 be seen are a few retractile granules. 13 to 15 : Encysted forms stained with 

 iron haematoxylin. The nucleus, cytostome with its flagellum and some granules 

 are clearly brought out. Size of cysts, 7 to 10 microns in length. 



FIGS. 16 to 18. A yeast which in shape and size closely simulates the cysts of 

 tetramitus. 



PLATE III. 



FIGS. 1 to 11. Tricercomonas intestinalis, n. g., n. sp. 



1 to 4 : Flagellate as seen in the living condition with three anterior flagella 

 and flattened side along which runs the fourth flagellum to become free at the 

 posterior extremity. 5 to 8 : Cysts which are probably those of the flagellate 

 with which they were associated. 9 to 11 : Flagellates as seen in stained films. 

 The flagellates are 4 to 8 microns in diameter ; the cysts 6 to 8 microns in 

 length. 



FIGS. 12 to 17. Iodine cysts as seen in stained films. The iodophilic body appears as 

 a vacuole. Often there is a difficulty in distinguishing cysts of E. histolytica. 

 The nucleus however is smaller than that of the E. histolytica cyst with single 

 nucleus. Fig. 15 : I-cyst without vacuoles. The cysts shown in the figures 

 measure 7 to 10 microns in longest diameter. 



FIGS. 18 to 23. Trichomonas intestinalis. 



18 : Pentatrichomonas form. 19 to 23 : Tetratrichomonas forms. 18 to 20 

 are from osmic vapour preparations, stained by eosin azur. 21 to 23 are from 

 sublimate wet fixed films stained by iron haematoxylin. 



PLATE IV. 

 FIGS. 1 to 20. Waskia intestinalis, n. g., n. sp. 



1 to 8 : Flagellates as seen in fresh preparations ; 1 : form with characteristic 

 bird-like appearance ; 2, 4, 6 forms showing cytostome with the thick flagellum 

 projecting from the cytostome and the single thin anterior flagellum. 3 and 5 : 

 Dividing forms. 7 and 8 : Structureless cysts of flagellate as seen in living 

 condition. 9 to 14 : Flagellates as seen in films fixed in sublimate and stained 

 by iron haematoxylin. 9 and 13 : Dividing forms. 10, 11, 12, 14 : Ordinary 

 type of flagellate. 15 to 20 : Encysted forms as seen in films fixed in sublimate 

 and stained by iron hsematoxylin. Some of the cysts show nuclear changes, 

 which may be indications of nuclear divisions. 19 : End view of cyst. The 

 length of the free flagellates is 4 to 9 microns, that of the cysts from 4 to 6 

 microns. 



