RUMINANTIA 345 



fine mould, and at once found my embryos in a high state of 

 activity. The mould, however, appearing too moist for the 

 earth-worms, I permitted further evaporation before closing the 

 jar with a glass cover. Four days subsequently I examined 

 the intestinal contents of two of the earth-worms. In one of 

 these, an inch in length, no parasite of any kind could be de- 

 tected ; but in the other, which was beyond three inches in 

 length, there were numerous Opaline besides several strongyle 

 embryos, the latter presenting characters not visibly in advance 

 of those still living in the mould. All of them were motionless, 

 as if they had not got over the shock produced by previous 

 cold. Moreover, the weather had again become cold, and thus, 

 when I again inspected my experimental embryos living in the 

 jar, I also found them motionless, so different from their 

 behaviour on the 4th. However, since a further result with 

 the earth-worm embryos appeared possible, I placed some of the 

 faecal matter, already ascertained to contain a few of them, on 

 the fronds of a thoroughly moist and dew-covered Asplenium 

 bulbiferum. This plant was in a fern-pan which had the advan- 

 tage of considerable fire- warmth during the day. When, how- 

 ever, on the 15th of November, I examined the fgecal earth 

 removed from several of the pinnules, I failed to find any of 

 the embryos. Possibly they had wandered, for the entire 

 frond was covered with dew-drops, which was not the case with 

 the fern that I had previously experimented on with such satis- 

 factory results. At all events, whether they had wandered or 

 had perished, their apparent absence in no way affects my pre- 

 vious record ; and the more so since only a few had been observed 

 in the fa3cal matter. The smallness of the number found in the 

 earth-worm was also readily accounted for. Thus, when at 1.30 

 p.m. on the 15th I made a diligent search for embryos in several 

 grains of the fine mould, not a single young strongyle could be 

 detected. Possibly the frost of the previous night had killed 

 them. The earth-worms were still alive and in good condition. 

 In conclusion, I may observe that every experimenter with 

 helminths is well aware how unfavorable the winter season is 

 for this kind of research. If a repetition of this inquiry in the 

 spring or summer should confirm these results, it will prove a 

 clear and substantial addition to our knowledge of the develop- 

 ment of the strongyles. Meanwhile, I think that the data 

 above given render it highly probable that the larvae of the 

 noose-producing strongyle (8. micrurus) are passively trans- 



