in Eudorina elcgans and Cryptoglena. 251 



viz. the unicellular Algae, it becomes interesting to inquire how far 

 the same process is likely to occur in the other families to which 

 it is allied. I have stated above^ that, from Cldamydococcus un- 

 dergoing a similar duplicative subdivision to Eudorina, it is not 

 improbable that it undergoes a similar mode of impregnation 

 also ; but in the fissiparation of Cryptoglena lenticidaris we find 

 such a resemblance to the compound groups of Cldamydococcus, 

 that it now seems more likely that it should resemble that of 

 Cryptoglena lenticularis. Again, I have stated that Trachelo- 

 monas, which is also a Thecamonadina, presents an appearance 

 of fissiparation in its internal cell, which might enable it to 

 undergo a fecundating process like Eudorina; but Trachelo- 

 monas, being loricated, is closely allied to Cryptoglena lenticularis^ 

 and therefore might rather be expected to undergo a fecundating 

 process like the latter. The notch and oblique fissure also ally 

 Cryptoglena lenticularis to the Euglena : but then the spiral- 

 fibre coat of this family could not give way for the elimination 

 of an internal cell with gonidia, like the lorica of the former ; 

 hence this fecundating process seems to throw no light on that 

 of Euglena, which has yet to be discovered, and no doubt will 

 be, sooner or later. But it is necessary to find out the time of 

 the year when these processes are likely to take place, and where 

 the organisms which are likely to be undergoing them make 

 their appearance annually, — after which the water should be 

 examined daily, immediately after the rain-falls ; otherwise those 

 which are required will be very likely to appear and go through 

 the fecundating process (just as fast as some plants flower and 

 seed) before their presence is even noticed. Hence, a place where 

 there is rain occurring regularly only once a year is best fitted 

 for these researches ; and I feel convinced that, had I had better 

 health and more leisure at the beginning of this "rains," I 

 should have been able to have done much more in this subject 

 than is above communicated. 



August 7th. 



P.S. — I have to-day seen the incorporation of the spermato- 

 zoid with the macrogonidium of Cryptoglena lenticularis take 

 place several times, and once so satisfactorily that I am able to 

 assert the fact without reservation. The former, after having 

 fixed itself upon the latter, assumes a conical or peg-top shape, 

 and thus gradually appears to squeeze itself into the macro- 

 gonidium. I have also ascertained that this spcrmatozoid has 

 two cilia, as I had before supposed. 



I would also notice here, that, in rating my micrometer, I 

 have just found out that the 5600th and 1900th divisions should 

 be 54-OOth and 1880th of an inch respectively. The reader is 



