RECORDS 7 



or less regular cycles of activity and weakness. (2) The period 

 of weakness is preceded by one of greater dividing-activity. (3) 

 The period of weakness ends in death, provided the diet (hay- 

 infusion) remains the same. (4) Beef-extract, without conjuga- 

 tion, restores the weakened functions of growth and division. 

 (5) Exogamous conjugation of A and B, if followed by the 

 same diet (hay-infusion), does not restore these weakened activ- 

 ities, but is soon followed by death. (6) Exogamous conjuga- 

 tion between wild gametes, and followed by hay-infusion diet, 

 results in normal growth, division, and life. (7) Endogamous 

 conjugation does not differ from exogamous conjugation. The 

 ex-conjugants live and divide normally if fed for a time with 

 beef-extract, but die if fed directly with hay-infusion. (8) One 

 intra-cellular effect of beef-extract upon weakened Parmnoeciuni 

 is the formation of " excretory granules." Another is the dis- 

 integration of the old macronucleus. (9) A few conclusions to 

 be drawn are : (d) a change of diet is necessary for the contin- 

 uance of vital activities ; iU) the equivalent of parthenogenesis 

 in higher animals may be induced by change in diet ; [c) conju- 

 gation, by itself, does not " rejuvenate " ; (c/) conjugation prob- 

 ably has some other significance than that usually accepted, 

 though what this significance may be is not indicated, thus far, 

 by the experiments. 



Professor Orampton presented the results of a statistical 

 study upon pupae of Saviia cecropia. Twenty-five characters 

 were determined for a lot of 456 pupae, the measurements were 

 tabulated, and the usual constants of the curves of variation 

 were ascertained, viz., the range, mode, mean, standard devia- 

 tion, and coefficient of variability. It was found that only 349 

 of these pupae produced perfect moths at the time of metamor- 

 phosis, the others being imperfect to a greater or less degree, 

 and therefore presumably eliminated as far as reproduction is 

 concerned. When, now, the former class was compared, sex 

 by sex, with the whole group of pupae, it was found to be a 

 selected class of the less variable individuals, while the more 

 variable ones were eliminated. Selection is therefore "periodic" 

 in the sense of Pearson. The fact of primary interest appears 



