174 MICROSCOPIC FAUNA. 



of maxillary palpi, and distinguish between what is and is not fit to 

 be swallowed. 



The Daphnia is extremely prolific, and with the most moderate 

 compilations, making the largest deduction for the number of 

 males, and for accidents to the young, a female Daphnia pulex will 

 produce 800 eggs in a year, or, as the females begin to lay when 

 three months old, 184,400 females will at the end of a year have 

 sprung from one parent. This fecundity is, however, outstripped 

 by the Cyclops quadricornis, which, according to Farine, will 

 produce 3,331,641,840 females in the space of twelve months. 



Let me just mention that I have found Plumatella repens, 

 Plate XIII., Figs. 9,10, and Lophopus, upon decayed wood lying at 

 the bottom of the canal. I need hardly say that these seem like 

 bits of jelly, shapeless, formless, lifeless, when taken out of the 

 water, but when placed in the zoophyte trough with some of their 

 oivn canal water, and left in quiet for a little, these bits of mucous- 

 looking substances will expand in groups of tentacles with cilia 

 coursing round" them, all in the same direction, and directing 

 currents of water into the common oral aperture. 



Of the family of Vorticellidse, there is to be found some of the 

 best species of the genus Vorticella, also Carchesium, Epistylis; 

 all these can be found when carefully searched for, and all of them 

 will repay study. I will only say, that the pedicle. Fig. 11, by 

 which these creatures are secured to their resting place, has not 

 received sufficient study. Saville Kent says, that with a power of 

 600 diam., the central muscle-like cord. Fig. 12, exhibits the 

 aspect of being finely and evenly striate transversely. And that 

 under 1,800 diam., these transverse striae become resolved into 

 parallel rows of minute longitudinal strict, having 10 in each row, 

 as seen in optical section. This muscle is disposed in an extended 

 spiral form within the hyaline sheath, and is continuous with a 

 delicate muscular sheet or layer, which passes up into the walls of 

 the body, and underlies the cuticle. 



The kingdom of the Rotifera is also well represented in the 

 Fauna of the canal ; indeed, for the finding of some of the most 

 interesting of these, I was indebted to a brother member, who told 

 me that in a certain spot 1 should find Carchesium, and when I 

 went there, I had a delightful haul of Melicerta ringens, Floscu- 



