530 



SCIENCE 



[N. S. Vol. XXXVI. No. 929 



drop, depending on the strength of the agent, 

 and a clear zone arises between this ring and 

 the general sperm suspension. The clear zone 

 is produced by migration of spermatozoa to 

 the ring; in case the agent is very strong the 

 ring expands, owing to immigration of sper- 

 matozoa, but the clear zone is never obliter- 

 ated, no matter how much the ring may ex- 

 pand. In the case of Nereis, which has un- 

 usually large spermatozoa, the passage of 

 spermatozoa across the clear zone to the ring 

 may be readily studied under a low power of 

 the microscope, and it gives the impression of 

 a regular rain falling on the ring. 



In the case of Nereis all acids tested are 

 aggregating agents (CO,, RSO,, HNO3, HCl 

 and CH3COOH were studied), but do not ag- 

 glutinate, and alkalis (K, OH and NaOH 

 only studied) are agglutinative but not ag- 

 gregative. The sperm of Nereis is ex- 

 tremely sensitive to acids, reacting positively 

 to iVr/1,000 H,SO., HCl, HNO3 and N/2,000 

 acetic, and to 1/200 dilution of a saturated 

 solution of CO. in sea-water. The phenomena 

 of aggregation were therefore studied, par- 

 ticularly in the ease of Nereis. The sensi- 

 tiveness of Arhacia sperm to acids is three or 

 four times less than that of Nereis sperm, but 

 the reactions are in the same sense. 



If an acid or other aggregative agent alone 

 be present in the drop tested in the suspen- 

 sion beneath a raised cover slip, the ring 

 which forms is perfectly continuous and the 

 individual spermatozoa are separate. If an 

 agglutinin as well as an aggregative agent be 

 present, the ring forms and breaks up into 

 agglutinated masses. If the agglutinin alone 

 be present no ring proper forms, or there is 

 no outer clear zone, and agglutinated masses 

 form within the drop as described. The egg- 

 secretions give the double reaction. 



V. Von Dungern's experiments (Zeitsch. f. 

 allgem. Physiologie, I., pp. 34^55, 1902) are 

 the only ones, so far as I know, in which the 

 production of sperm agglutinins by ova was 

 investigated, and he discovered only hetero- 

 agglutinins, no iso-agglutinins. He did, in- 

 deed, describe the loss of motility of sperma- 

 tozoa in egg-extracts of the same species, but 



he entirely missed the phenomenon of agglu- 

 tination and its reversal. He reveals the rea- 

 son for this failure by his remark that he 

 always examined for the effect of the "egg- 

 poison " about half an hour after its addition 

 to the sperm; but the phenomenon of agglu- 

 tination and its reversal are completed in 

 about five minutes. 



Von Dungern also made experiments on the 

 production of immune sera by injection of 

 ova and spermatozoa separately into rabbits, 

 and found that both caused the production of a 

 sperm agglutinin in the rabbit's serum. From 

 this he concludes that both kinds of reproduc- 

 tion elements possess chemically identical 

 complexes of molecules in the protoplasm. 

 While this may be admitted as at least a very 

 probable conclusion, his farther conclusion 

 that fertilization does not depend upon any 

 specific antagonism between ovum and sperm, 

 but is conditioned by the similarity of their 

 protoplasms, is not well founded, for the egg 

 is a very complicated chemical system, and 

 it certainly contains molecules antagonistic to 

 sperm, even if, as von Dungern's experiments 

 indicate, it also contains some that are not. 



VI. The existence of sperm iso-agglutinins 

 in ova offers the possibility of an explanation 

 of the specificity of fertilization on the basis 

 of the laws governing antigens and anti- 

 bodies, if these agglutinins are specific, as is 

 so strongly suggested by the experiments. 

 The union of ovum and spermatozoon is not 

 a process in which the sperm penetrates by 

 virtue of its mechanical properties, but one in 

 which a peculiarly intimate and specific bio- 

 chemical reaction plays the chief role. A later 

 publication will give the details of the experi- 

 ments and a more complete analysis of the 

 behavior of the spermatozoa in fertilization. 

 Frank E. Lillie 



September 16, 1912 



PRELIMINARY NOTE ON PRISTINA AND NAIDIUM 



These two genera, Pristina and Naidium, 

 of the aquatic oligochtetes, have been com- 

 bined and separated by recent systematists 

 with quite startling rapidity. The former 

 genus was first described by Ehrenberg in 



