202 



HARDWICKE'S SCIENCE-GOSSIP. 



ventral nearly flat ; the two divided by a deep, 

 lateral, longitudinal sulcus, covered with flexible 

 membrane ; toes two, or one (Monostyla) always 

 exposed." The characters of the genus Cathypna, 

 are as follows — •" Lorica sub-circular horizontally, 

 usually much arched vertically, lateral inangulation 

 wide and deep ; toes two, furcate." The genus 

 Distyla is said to differ only "in the latter inangula- 

 tion being feeble;" and having "selvage-like 

 thickenings of the lorica around the foot." Mr. 

 Gosse says that "the genus is closely linked with 

 Cathypna, yet the flattened form, the habitual 

 protrusion of the head, and the more constant 

 activity of the species distinguish it." Now in these 

 remarks, Mr. Gosse seems as if he were trying to 

 convince himself, and he appears quite conscious of 

 the necessity to point out very particularly the points 

 of difference lest they should be overlooked. It will 

 be seen how really slight these differences are, and 

 as it will greatly assist us, if we rightly comprehend 

 the differences said to exist between the two genera, 

 I recommend microscopists to study the descriptions 

 and figures published in the work referred to. I have 

 myself prepared drawings of two species, upon 

 which I more particularly found the conclusions 

 arrived at in this paper. 



We are now in a position to take Mr. Gosse's 

 points seriatim. In both my specimens the lateral 

 inangulation, and the arched dorsal plate are as 

 strongly marked as in Cathypna (See Fig. 115 b). 

 The form of the lorica both in mine and in Ehrenberg's 

 D. Hornemanii, is as broad ; and as to their activity, 

 this is exhibited only when the animals are excerted : 

 when retracted they are as characteristically sluggish. 

 There only remains to note the distinction as to the 

 "habitual protrusion of the head." This seems to 

 me so abnormal a condition as of itself to cause 

 suspicion. That an animal should have developed a 

 protecting lorica, and that this should protect only 

 its least vulnerable part, leaving exposed the whole 

 of the forepart, with its enclosed brain and sense- 

 organs — seems to require an explanation not as yet 

 forthcoming. The Rotifera of the genus Cathypna, 

 indeed, I might say of the fam. Cathypnadse, are 

 excessively lethargic ; they may be watched for long 

 periods, either asleep, or sluggishly moving their 

 toes or languidly swaying to and fro without excert- 

 ing their frontal part. I have myself had them 

 under occasional observation for a week at a time, 

 without seeing any other signs of life than the languid 

 movements described. When however they do exert 

 their frontal part, they are as vigorous as their 

 congeners : and here, I believe, we have the expla- 

 nation of the probable error. Late in the year 1886, 

 I was examining some water and sediments from my 

 now historic " Prolific Pond," when I saw a 

 Rotiferon extended, which was new to me, of which 

 I give a drawing (Fig. 115 c). This I watched at 

 intervals for an hour or two without at all suspecting 



its relation to Cathypna, or indeed that it was a 

 loricated form at all ; when, from some unknown 

 cause, the frontal part was suddenly retracted, and I 

 at once recognised the animal so familiar to me in 

 the earlier part of the year, which I had figured and 

 described in SciENCE-Gossir. (Fig. 115 a & b) in 

 my " Notes on the Genus Euchlanis." Fig. 116 a & b 

 occurred subsequently in the same water, and differs 

 from Fig. 115 chiefly in its shorter toes, and in the 

 anterior points on the lorica. How a Rotiferon with a 

 lorica (like Fig. 1 15 a & b) can lengthen itself out in the 

 manner depicted in Fig. 115 c, I cannot fully compre- 

 hend, but that it does so is indubitable. The lorica, 

 I take it, must be excessively thin and membranous. 

 Any one seeing a Rotiferon of my species of Ca- 

 thypna extended, and in vigorous motion might easily 

 be pardoned, if, remembering the broadly-oval form 

 and sluggish habits of the Cathypna, he concluded 

 he had under observation an animal of a different 

 genus. It is of course possible that Distyla may 

 be a good genus, but it is, I think, at least probable, 

 that some, if not all the species of that genus have 

 been described from extended Rotifera of the genus 

 Cathypna. Dr. Hudson somewhat complacently 

 remarks that he has now managed to get every 

 known Rotifer into his net ; but my two species are, 

 I believe, new, and I propose to name Fig. 115 Ca- 

 thypna Gossei, & Fig. 116 C. Hudsoni. Both closely 

 resemble the Euchlanis (Distyla) Hornemanii of the 

 illustrious Ehrenberg, and it is very significant that 

 he describes that species as being "soft, flexible, 

 elongated, and capable of retraction." I submitted 

 my drawings and Notes to Mr. Gosse, who was very 

 much impressed, and urged me to follow up the 

 investigation and let him know the result. Unfortu- 

 nately, two large bleach-works were started in close 

 proximity to my " Prolific Pond " and very effectually 

 put an end to my researches. It does not require a 

 phenomenal knowledge of chemistry and biology to 

 know that Rotatorial life and chlorine, and many of 

 its compounds are incompatible. I trust that those 

 microscopists who have the opportunity will take up 

 the investigation of this subject, and whether the 

 result be to confirm the genus, or my suspicions as to 

 its non-existence, my purpose in writing these Notes 

 will have been accomplished. 



J. E. Lord. 

 Rawtenstall. 



THE COLOUR AND FERTILITY OF BIRDS' 

 EGGS. 



IN a previous issue of this journal I ventured to 

 state that there was a strong relation between 

 the colour and fertility in the eggs of wild birds. I 

 again beg to offer some further remarks, which may, 

 perhaps, meet with the same severe criticism. 



However, from observations I have been able to 



