INDUSTRIAL PROGRESS DURING THE YEAR 1874. cxxxv 



Toward the end of the summer, when heavy rains set in, and 

 the temperature decreases, the Artemia becomes larger, loses 

 its red and gray color, and becomes clear and transparent, 

 so that the July generation has important differences from 

 that which appears in November. In order to observe this 

 phenomenon carefully, he undertook the artificial breeding 

 of the Artemia in two different ways. In one vessel he in- 

 creased the saltness of the water up to 18 Baume, in anoth- 

 er he reduced the solution to 3, and thus reared several gen- 

 erations. In both cases, he remarked that each new genera- 

 tion easily lived in such a concentrated solution as the pre- 

 vious generation could scarcely live in. By raising them in 

 so different solutions (1 8 and 3 Baume), very different forms 

 of Artemia were obtained, which were not to be found in 

 their original pond. 



" While carrying on these observations, he at the same 

 time proved that a parthenogenetic reproduction exists in Ar- 

 temia. Each time, both in the great increase of the weak 

 solution as well as in the greatly increased saltness of the 

 water, the females produced new generations, despite the ab- 

 sence of the males. Under these relations of the solutions, 

 in warm weather only females were produced. These fe- 

 males produced in similar breeding -jars only female off- 

 spring. Only in water of medium strength were produced 

 males." 



As a further illustration of the influence of physico-chem- 

 ical surroundings on the organization of these animals, I will 

 again quote from the abstract of the remarks of our author: 

 "In the salt-pools in the neighborhood of Limans (near Odes- 

 sa), he found in the spring, together with Branchipus (Arte- 

 mia) ferox, Gr., a very peculiar Artemia, which he thought 

 was undescribed. He thought from certain characters that 

 this species belonged to the higher group of Branchipus. In 

 this form he observed some strange differences in the struct- 

 ure of the sexual organs, changes which could scarcely be re- 

 garded as pathological. Usually, the horns (lower anten- 

 nas) of the females are small, but in the old females they are 

 clearly elongated, and are very much like the claspers of the 

 males. Still earlier appears a striking change in the struct- 

 ure of the genital organs, wherein some characteristics of the 

 male organs appear. In like manner, the sexual organs are 



