64 ILLINOIS BIOLOGICAL MONOGRAPHS [282 



solcher einzelner KnoUen." Tyzzer states further that "the basis for differ- 

 entiation of an American species at the present time appears therefore to 

 be rather inadequate." That he is dealing with the same species as that 

 reported by Cole (1911) and later named Collyriclum colei by Ward (1917) 

 cannot be doubted and according to his statement his material "is un- 

 doubtedly of the same species," 



Although Tyzzer failed to find any difference which would warrant a 

 second species of Collyriclum the present investigation has shown that 

 except in minor detail the work of Jegen agrees with that of Kossack, and 

 on the basis of the descriptions of these investigators the American mate- 

 rial is distinct from Collyriclum faba in that the testes are lobed and in the 

 asymmetry and extent of development of the vitellaria. It is impossible 

 to explain away these differences either as "artefacts in preservation" or 

 as "individual variation," nor is it probable that both Kossack and Jegen 

 have overlooked these features. On the basis of these difference the Amer- 

 ican material must be recognized as a distinct species under the name Colly- 

 riclum colei Ward. 



A preliminary study of specimens of Collyriclum faba secured by Pro- 

 fessor Ward bears out the description of Kossack and Jegen as well as the 

 conclusions of the writer drawn from the study of their papers and compari- 

 son with American specimens of this genus. A more thorough study of the 

 European material is not feasible at this time but is anticipated at an 

 early opportunity. 



REMARKS ON THE LIFE HISTORY 



The life history of Collyriclum faba is doubtfully known. Tyzzer gives 

 a careful description of the development of the egg of Collyriclum colei 

 from the time of fertilization to maturity in the end portion of the uterus. 

 Regarding the mature eggs he says "The eggs stored in the terminal por- 

 tion of the uterus evidently contain miracidia, the morphological features 

 of which are not clear in fixed material owing to imperfect preservation 

 and shrinkage." He continues with a description of the "hair-like" 

 structures which have been distinguished. This adds evidence that a 

 miracidium is present. 



The work of Jegen (1917) which is an attempt at the life history of 

 Collyriclum faba differs radically from the statements of Tyzzer in that he 

 finds the eggs contain two embryos which are not miracidia but young 

 trematodes; these need only to be incubated in the intestine of the host 

 that they may break out of the egg shell and freed with the excrement, 

 may wander into the feather follicle. He found also cysts (Dauercyste) 

 which after a longer period of incubation break open and the worm enters 

 the follicle of a feather. Jegen summarizes his work as follows: "Die 

 Eier von Collyriclum faba werden durch den Wirt mit dem Parasiten aufge- 



