390 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Bi-parental Inheritance in Paramoecium.* — H. S. Jennings and 

 K. S. Lashlej have been able to demonstrate that bi-parental inheritance 

 exists in Parammcium as a result of conjugation. 



After conjugation a considerable number of the lines of progeny 

 descended from the conjugants die out or are weak. In many of these 

 cases the lines descended from the two members of a pair differ in 

 their fate, one dying or reproducing slowly, while the other lives and 

 reproduces vigorously. It has been held that this indicates an in- 

 cipient sexuality — the " male " reproducing little or not at all, the 

 " female " reproducing vigorously. The two members of the pair 

 were thus held to be less alike in their vitaUty and reproductive power 

 than would be the case if the deaths and the variations in reproductive 

 power were distributed without reference to the pairing. 



The tenability of this interpretation has been carefully tested by 

 a method of analysis. It has been found (1) that conjugation has the 

 effect of making the progeny of the two members resemble each other 

 in vitality ; and (2) that conjugation has the effect of making the 

 progeny of the two members alike in their reproductive power. 



These relations give no evidence for sexuality considered as a 

 tendency for the two members of a pair to be diverse in vitality and 

 reproductive power. The condition actually existing is the reverse one. 

 What they show is that bi-parental inheritance occurs as a result of con- 

 jugation, the vitality and rate of reproduction being affected by both 

 parents, so that the progeny of the two resemble each other in these 

 respects. 



Explosion of Starved Ciliata-f — Emile Yung subjected various 

 Ciliata {Paramecium caudatum^ Frontonia Imcas, and Stylonichia ])n,8- 

 tulata) to a prolonged fast, and observed the effects on the minute 

 structure. In the two species first named a peculiar phenomenon was 

 observed after a complete fast of 11 to 21 days. Under the influence of 

 a knock, or the vibrations of a metal plate, the Infusoriaus underwent a 

 sort of explosion, so that only shreds of membrane and granular debris 

 remained. It may be that abundant explosive " trichoplasm " is pro- 

 duced during the starving period. The whole organism explodes just as 

 a trichocyst does. 



Fla^ellata and Ciliata of Clare Island and District.^ — J. S. 

 Dunkerly reports on a collection of fresh-water and parasitic Infusorians. 

 Ninety species are recorded for Ireland for the first time ; about twenty 

 are probably new to Britain. Two new species of Le'ptomonas, parasitic 

 in insects, are described. Among the interesting forms are : — Mastiga- 

 mmha mverteris, M. butschlii, MulticiUa palnstris, Anthophysa vegetans, 

 Monas vivipara, Sennia commatata, Petalomonas steinii, Gyrocoris 

 oxyura, and Vaginicola hiltschUi. 



* Journ. Exper. Zool., xiv. (1913) pp. 393-466 (2 figs.). 



t Il6sum6s des Communications, 9e Congres Zool. Monaco, 1913, ser. 2, p. 8. 



+ Proc. R. Irish Acad., Clare Island Survey, Parts 61-2 (1913) pp. 1-20 (2 pis.). 



