Dobell, Some Kemarks upon the „Autogamy" of Bodo lacertae (Grassi), 553 



Beyond this stage I did not follow the growth of the organisms. 



There can he little douht that these cysts have nothing whatever 

 to do with the Protozoa living in the frog's gut — that they are 

 onthe contrary, yeasts, or vegetable organisms allied to 

 the yeasts. 



What, then, are the „chromidia"? From their general behaviour 

 and reactions I think there can be little doubt that they are some 

 kind of reserve material, which is largely — if not entirely — 

 used up in germination. Though the material varies in form — being 

 sometimes in strands or rodlets, sometimes in large lumps, etc. — 

 its arrangement in the cell appears to me to be entirely adventitious. 

 When it is absent, uninucleate cysts are presented — the first stage 

 in our arbitrary arrangement of the cysts (Fig. 1 a). When the 

 granules lie round the nucleus, an appearance suggesting the for- 



Fig. 6. 



mation of chromidia is seen (Fig. 1 b, c). When the granules are 

 in pairs — a not uncommon condition — we see the formation of 

 „reduction nuclei" (k, I, ni etc.). And so on: all stages are to be 

 found if one looks for them. 



When I had reached these conclusions, the conviction forced 

 itself upon me that Prowazek had really committed the error of 

 describing similar organisms as stages belonging to the life-cycle 

 (autogamy) of Bodo. The resemblance, amounting almost to iden- 

 tity, appears to me to be too close to be accidental. Dr. Pro- 

 wazek himself would, I am sure, be one of the first to acknowledge 

 the ease with which such a mistake might be made. The difficulties 

 of singling out the stages in the development, of one organism 

 from a great number are often very great. 



The following points now reqnire to be considered from this 

 new point of view. 



