PACKARD.] PAKTHENOGENESIS IN ARTEMIA. 465 



To verify whether those eggs were really umferiilized^ I arranged 

 another large jar with artificial sea water and marked it with/. Into 

 this jar I placed some Triest marine mud which had been j)reviously 

 boiled to destroy any eggs possibly contained therein. The adult 

 females placed in this jar prospered well. The uumber of adult females 

 in jars a and h continually increased, counting, on February 1, 24 fe- 

 males, all with brown eggs in their egg-sacs. Six of these females 

 dropped their eggs on February 5, their ovaries again showing activity. 



1 again arranged another jar, beaiing the letter A, placing previously 

 boiled mud into it and those 6 females, whose egg-sacs, on February IG, 

 contained for the second time brown eggs, and again the same day I 

 I)laced 8 more specimens into it, taken from jar /, which afterwards 

 prepared themselves for a third oviposition, so that 1 was urged to take 

 for those 14 females another moderately large jar, bearing the letter *, 

 to allow them to dei)08it for a third time. On March 2 this jar i was 

 arranged with the 14 females, the latter depositing their eggs during 

 March ; on April 15 ajar marked m was prepared with boiled mud, i)lacing 



2 females into it from jar i, which were about to deposit for the fourth 

 time. On May 4 one of the two deposited for the fourth time, and al- 

 though a fifth series began to form, I did not prepare another jar; the 

 specimen showed great weakness, and died subsequentlJ^ 



As a matter of course the females taken from jars a and h multiplied 

 in the jars/, ^, i, m. In jar/, out of which I took, up to February 28, 

 14 females and placed them into jar /i, I C(mnted, on April 6, 39 females. 

 It would be too tiresome to put down here all the notes as I wrote them 

 down seriatim in reference to further dcvelojiment of Artemia, and I 

 shall here briefly state the result of my experiments. The eggs were 

 for the greater part on the suiface of the muddy bottom. On March 

 16, being the 40th day after my first raised virgin Artemise deposited 

 their eggs, I noticed two embryos of the jSTauplius-stage, as figured 

 by Joly. For the sake of maintaining stricter control ot the embryos, 

 of whose parthenogenetic origin I had to be fully convinced, I placed 

 these, as well as all those later hatched in jar/, into a smaller jar, </, 

 with some previously boiled Triest mud. On March 24 I had eight 

 such embryos in jar g ; counting on March 30, 22; and up to May 10 I 

 had transferred 71 embryos from jar / into jar g. Henceforth tlie de- 

 velopment in jar / increased rapidly (May 11, hatched 25, and May 12, 

 49 embryos), so that up to May 23 I obtained from jar / 402 embryos. 

 In this manner I verified that from eggs dq)osltcd hy virgin females of Ar- 

 temia salina^ which were not fertilised hy any mole sperm, a brood can de- 

 velope. The empty egg-shells were found to be partly floating on the 

 surface or hidden in the mud at the bottom. The fresh iinhatched Qgg 

 never swam on the surface, and the empty egg-shells on the bottom all 

 showed a crack. 



Seventeen embryos were removed from jar g and placed in a jar 

 marked /c, with a quantity of prepared (boiled) Triest mud. This was 

 done for better observing the sexual development. Of these 17 indi- 

 viduals 5 were nearly full grown on Aj^ril 30, with no indication of ova- 

 ries, though with beginning egg-sac formation; two other individuals 

 of those 17 Artemiae did not yet show, though full grown, any sexual 

 differentiation. 



On May 10 I transferred from jar A; those specimens which approached 

 sexual maturity into a jar marked o, together with some uupre])ared 

 fresh water clay-mud. These 14, in jar o transferred Artemiae develop- 

 ing into egg-bearing females, prospered well in the salt water of the new 

 jar, and filled, as usual, their intestine with mud as if they had hadma- 

 30 H 



