3. Die höheren Lebenseinheiten. 433 



the United States and Canada of Clinostomum marginatum, a 

 Trematode Parasitic in Fish, Frogs and Birds. 



(Biol. Bull. 20,6. p. 352— 368. 10 figures. May 1911.) 

 „(1) The first host and early life-history of C. marginatum are entirely unknown. 



(2) It passes a period of quiescence encysted in the muscle tissue of 

 various predaceous food fishes and in the lymph-spaces of frogs, in various 

 localities ranging from Missouri through Ohio to Pennsylvania, and north as 

 far as Minnesota, Michigan and Ontario, Canada. 



(3) It finally reaches an avian host which is some fisk-eating bird, such 

 as the bittern or the heron. 



(4) The cyst in the fish is a connective tissue structure produced from 

 the endomysium of the host with a spezial vascular equipment. 



(5) The living worms on being artificially liberated from the cysts per- 

 form characteristic movements adapted to finding locations in the final host." 



Lillie (Chicago). 



1183) Matruchot, L. (Laboratoire de botanique de l'Ecole normale superieure 

 de Paris), Un nouveau Champignon pathogene pour l'homme. 



(Cornpt. Rend. Acad. des Sciences de Paris 152,6. p. 325—327. 1911.) 

 II s'agit du Mastigoclonium Blochii sp. n. isole de chancres verru- 

 queux, et qui est un ascomvcete de la famille des Hypocreacees. 



C. L. Gatin (Paris). 



1184) Arzb erger, E. (*., The fungous root-tubercles of Ceanothus 

 americanus, Elaeagnus argentea, and Myrica cerifera. 



(Annual Rept. Mo. Botanical Garden 21. p. 60—102. pls. 6—14. 1910.) 

 In Ceanothus, tubercles were found on the plants wherever examined, so 

 that infection by the fungus is probably universal. The tubercles on this 

 plant contain an inner vascular cylinder surrounded by a cortex bearing the 

 infected cells, around which is a corcy outer layer. The mycelium of the 

 fungus enters the cells of the host and finally produces sporangia within these 

 cells. All of the reserve material and finally the protoplasm and nucleus of 

 the host cells is used up by the fungus which then, having killed the host 

 cell, dies of starvation. The host cell gradually loses its turgidity and is dis- 

 placed by the surrounding cells. A condition of symbiosis between fungus and 

 host cells exists in the early stages. 



In Elaeagnus the tubercles are less abundant than in Ceanothus, and the 

 fungal mycelium is much narrower. When the fungus enters a cell the 

 nucleus of the latter becomes larger, followed by growth of the cell wall, the 

 disappearance of the starch content of the cell, and the formation of dense 

 cytoplasmic masses in parts of the cell. The nucleus and cytoplasm of the 

 infected cell seem to grow simultaneously so as to maintain the nucleo-cyto- 

 plasmic relationship. This is a period of symbiosis, during which both the 

 fungus and the host cell prosper. Vesicles or sporangia are then formed by 

 the fungus, and host cell and fungus both finally die, but the walls of the 

 host cell are not broken down. 



All the species of Myrica were found to possess tubercles, but they differ 

 in many respects from the other forms. The fungus is confined to one or 

 two layers of cells. There is no hypertroph)- or symbiosis, the fungus being 

 best regarded as a parasite. The unicellular hyphae form branches which 

 become club-shaped, the fungus probably belonging to the genus Actinomyces. 



Enzymes capable of digesting fibrin were found to be present in the tu- 

 bercles of Alnus and Ceanothus. Whether there are two enzymes, one produced 

 by the fungus and another by the host, was not determined. Gates (London). 



