638 



SUPPLEMENT 



so much as in stringing together hard names,, 

 and in weaving learned labyrinths which shall 

 be " caviare to the general." 



In our first chapter we remarked that 

 molecular activity closely resembles the vital- 

 ity of the infusorial monads, and stated our 

 intention of returning to the subject. We 

 shall in this place offer only a few incidental 

 observations. So far as the mere activity is 

 concerned, the movements of the monads and 

 molecules are apparently identical ; there 

 may, notwithstanding, on a careful examination, 

 be discovered an evident voluntary action on 

 the part of the monads, which cannot be de- 

 tected in the molecules ; these latter obviously 

 act upon each other, the former act independ- 

 ently of each other. All supposed identity 

 between molecular and monadic motion, is, 

 however, we conceive, entirely overthrown by 

 the recent discovery of the polygastric struc- 

 ture of infusoria. The monads, it is ascertained, 

 have polygastric sacs similar in principle to 

 those of the larger animalcules, regarding 

 whose animal vitality there can be no ques- 

 tion ; consequently we have a right to infer, 

 from analogy, that the monads, though placed 

 at the extreme limit on the descending scale 

 of animality, are not mere active atoms, but 

 really organized animal bodies ; and indeed 

 it is tolerably well ascertained that these 

 monads pass into other forms and are ulti- 

 mately developed in the larger and less 

 equivocal animalcular existences. 



CHAP. III. 



SPERMATIC ANIMALCULES. 



TOWARDS the close of the seventeenth cen- 

 tury the existence of seminal animalcules was 

 discovered and made known to the world by 

 Leeuwenhoeck and Hartsoeker, each of whom 

 claimed the honour of being the first observer. 

 The former micrographer, if he did not orig- 

 inate the discovery, at least explained and 

 illustrated it to a much greater extent than 

 his contemporary ; and he has consequently 

 been considered as the leading authority on 

 the subject. The hypotheses and contro- 

 versies which arose out of the inquiries regard- 

 ing spermatic animals, are interesting to the 

 natural historian ; and though, in a popular 

 work, the subject must be approached with 

 caution, it is still desirable that some general 

 information should be given concerning these 

 vital germs, whose existence is undeniable, 

 though their relation to the mature animal 

 has not even yet been ascertained. 



Before the discovery of animalcules in the 

 semen mascitlinum, the egg system, as it was 

 termed, obtained universal consent. It was 



asserted that the female ovaria contained eggs, 

 waiting only till a principle of life was com- 

 municated to them by the other sex, when 

 the previously formed foetus would burst 

 through these receptacles and claim their 

 birth. When the existence of spermatic ani- 

 mals was announced, a system entirely oppo- 

 site in principle was earnestly contended for 

 by many of the leading philosophers of the 

 day. The new hypothesis considered the 

 seminal animal to be identical with the 

 mature foetus, and that it needed only for its 

 perfect developement, a suitable nidus, which 

 was provided in the uterus of the female. 

 The advocates of each system contended 

 strenuously for its support ; but the data in 

 either case were insufficient to decide the pro- 

 blem of generation, and both parties continued 

 to argue hypothetically, advancing with every 

 fresh argument still nearer to the climax of 

 absurdity. At the present day we have no 

 certain knowledge concerning the mysterious 

 process by which the succession of animated 

 creatures is secured, and the intent of the 

 spermatic animals is still matter of perplexity. 

 These vital germs do, however, exist in the 

 seminal fluids of all animals, from the largest 

 to the least ; and it is to their mere existence 

 that our further remarks will principally be 

 directed. 



Mr Leeuwenhoeck observed in the semen 

 of the human species, not less than ten thou- 

 sand living creatures, contained in a portion 

 of the fluid equal in surface to a grain of sand. 

 " Their size was smaller than the red globules 

 of the blood, and even less than the millionth 

 part of a grain of sand. Their bodies were 

 roundish, somewhat flat before, but ending 

 sharp behind, with tails exceedingly trans- 

 parent, five or six times longer, and about 

 five times more slender than their bodies. 

 They moved themselves along by the violent 

 agitation of their tails, in various bendings, 

 after the manner that eels and serpents swim : 

 and sometimes their tails were moved thus 

 eight or ten times in getting forwards the 

 diameter of a hair." Their shape may be 

 more popularly described as being very nearly 

 that of the tadpole. The seminal animalcules 

 of all living creatures, that have been ex- 

 amined, bear strong resemblance to each 

 other ; the size likewise does not vary accord- 

 ing to the disproportion of bulk in different 

 animals, and hence they are readily discovered 

 in the semen of birds, fishes, and insects. 



" Upon viewing the milt, or semen mascul- 

 inum, of a living cod-fish, such numbers of 

 animalcules were found therein, that at least 

 ten thousand of them were supposed to exist 

 in the quantity of a grain of sand. Whence 

 Mr Leeuwenhoeck argues that the milt of 

 that single cod-fish contained more living 



