3. Die höheren Lebenseinheiten. 567 



free life under stones in the bed of the stream. The number of worms con- 

 tained by a single larva is usually only one, but as many as twelve have 

 been found. A single worm measures 3 cm, which is about three tiraes the 

 length of the host. In some streams 25 per cent of the larvae were iufested 

 with this parasite. Parasitized larvae never pupate, but are killed by the 

 worms when they escape. 



The retardation in the development of the histoblasts is the opposite 

 condition to that met with in prothetely which is usually caused by keeping 

 larvae at an abnormally high temperature. This probably results in an in- 

 creased supply of the enzymes which cause these histoblasts to develop. The 

 Mermis apparently excretes some substance which lessens the supply or action 

 of these enzymes and leads to metathetely. 



The Sporozoön parasite occurs in several forms in different localities. All 

 these forms, however, live in the same way and appear to be related to the 

 pebrine disease of Lepidoptera. The body, especially near the apex of the 

 abdomen, becomes much distorted and swollen on account of the interior 

 being closely packed with a white wooly material which on dissection is 

 seen to consist of countless ,spores' of minute size. Such parasitized larvae 

 are usually rather smaller than healthy individuals, but the histoblasts do not 

 appear to be much affected. The parasite usually enters the body cavity in 

 the same manner as that described in the case of Mermis. Evidence of this 

 is seen in a hypertrophied condition of parts of the mesenteric wall. From here 

 it seems to pass to one or both of the sexual organs which are destroyed 

 and become the nuclei for the great mass of spores which eventually fills the 

 abdomen. The parasitized larvae in this case also were never observed to 

 pupate but died when mature. The spores are liberated by a rupture of the 

 abdominal wall soon after the death of the host and pass into the water, 

 after which stage they have not been seen. Up to 80 per cent of the larvae 

 in some streams were found to contain large masses of this parasite but no 

 cases of slightly parasitized larvae were observed. There has been no second 

 brood of Simulium larvae this year, so it would seem that if the parasite is to 

 appear next year there must be a secondary host in which the summer is passed." 



In a postscript the sporozoön parasite is identified as a new species of 

 Glugea, for which the name Glugea polymorpha is proposed. 



Lillie (Chicago). 



1580) Grimme, Die Askariden des Pferdes und ihre Bekämpfung 

 mit Tartarus stibiatus. 



(Deutsche Tierärztl. Wochenschr. 19,16. p. 247— 249. 1911.1 



Neben therapeutischen Bemerkungen — der Verf. tritt für die Anwendung 

 des Brechweinsteins ein — enthält die kleine Arbeit wichtige Notizen über die 

 Biologie der Askariden des Pferdes, besonders über die Möglichkeit der Über- 

 tragung. Pfeiler (Berlin). 



1581) Minchili, E. A. and H. 31. Woodcock (London University), Obser- 

 vations on the Trypanosome of the little Owl (Athene noctua) 

 with remarks on the other blood parasites occuring in this bird. 



(Quart. Journ. Micr. Sei. 57,2. p. 141—185. 2 plates. 1911.) 



Observations on the Trypanosome of the Little Owl (Athene noctua), with 

 remarks on other Protozoan Blood-parasites oecurring in this Bird. 



Doncaster (Cambridge). 



1582) Schuberg u. Kuhn, Über die Übertragung von Krankheiten 

 durch einheimische stechende Insekten. 



(Arbeiten aus dem Kaiserl. Gesundheitsamt 31,2. p. 377— 393. 1911.) 



