832 



SCIENCE. 



[N^. S. Vol. XVIII. Xo. 4G9. 



remains of meal-worms, etc., were very neatly 

 piled up in a particular corner of the middle 

 chamber: — in brief, the life and activity of the 

 ants were j^erfectly normal, notwithstanding the 

 rather peculiar provenience of most of the inmates 

 of the nest. 



During the normal course of colonial life the 

 following occurrences were noticed : 



During the last week of August, as it were on 

 the very day, when in the gardens and streets of 

 Frankfurth, winged males and females of Lasius 

 niger creep about as weary relicts of the nuptial 

 flights, about a dozen fine, shining males hatched 

 in my colony. When they had taken on their 

 adult coloration, they sought the illumined cham- 

 ber and walked about nimbly. Had it been 

 possible for them to escape, they would certainly 

 have joined in the nuptial flight of the mass of 

 their species out-of-doors. 



The males lived only a few weeks; most of 

 them met with an accidental death through be- 

 coming glued down with their wings. 



The colony passed the winter in good condition, 

 and in the spring of 1900 a rapid increase again 

 took place from eggs laid by the workers. On 

 the 1st of August I was able to announce to our 

 natural history society that the nest again con- 

 tained 300 workers and two to three dozen males. 

 This year, also, the appearance of the males coin- 

 cided with the swarming time out-of-doors. 



During the year 1901 the same events were re- 

 peated, with the difference that the number of 

 individuals had fallen off; still there were a few 

 males towards the end of July. By the spring 

 of 1902 only about twenty workers survived; 

 larvje were still being reared, but towards the end 

 of Ajjril, for some unknown reason, the whole 

 colon}' became extinct. ■ 



Worthy of note, therefore, is the coincidence, 

 three times in succession, in the appearance of 

 males at the typical time of sivarming for our 

 neighborhood. From this we must conclude that 

 the conditions in my colony did not depend on 

 degenerative or similar causes. On the contrarj', 

 this decided periodicity points to normal pro- 

 cesses, which probably also occur in wild colonies, 

 ^vhose workers, in all likelihood, take part in 

 producing males. Of course, these conditions re- 

 quire further investigation. 



He wlio takes for granted the completeness of 

 our knowledge of propagation in ants, more 

 particularly of mating and fertilization, will re- 

 gard all the workers of my Lasius colony as hav- 

 ing developed from unfertilized eggs. But the 

 question ari.ses, whether, after the males made 



their appearance, some kind of copulation could 

 not take place within the nest, or whetlier, in fact, 

 some of the eleven workers that founded the 

 colony were not fertilized. Many will deny this 

 with indignation and horror; but one is becoming 

 accustomed to surprises, especially in sexual phe- 

 nomena. Moreover, fertilization always occurs 

 normally within the nest in the case of Anergates 

 atratulus Schenck, which exhibits strict in-and-in 

 breeding. Forel also opens up this question 

 (■ Les Fourmis de la Suisse,' p. 401). At any 

 rate, a careful anatomical and microscopic anal- 

 j'sis of the ovipositing workers, which are per- 

 haps to be regarded as ergatogynous females, and 

 their eggs, is in every respect important, and 

 this alone would give value to the above observa- 

 tions. 



That Reiclienbacla's supposition of a fertil- 

 ization of the worliers by their male progeny 

 in his nest is unnecessary, is shown by the fol- 

 lowing observations kindly sent me by Mrs. 

 A. B. Comstock, and published with her con- 

 sent : 



About the middle of August I colonized some 

 .ants of the species Lasius niger L. var. ameri- 

 ccimis Emery, in a glass nest in my room for the 

 purpose of giving my pupils in nature study an 

 opportunity for observing the habits of ants. I 

 found this species common under the stones on a 

 dry side hill, and I brought in, with the workers, 

 pupsE and larvae of two sizes and some eggs still 

 unhatchdd. My prisoners soon put their nest in 

 order and placed the pupoe in two separate heaps, 

 and separated the larvte into two groups accord- 

 ing to size, and also placed the eggs by them- 

 selves. After a day or two the eggs hatched 

 and these young larvae were kept in a group away 

 from the others. A few days later more eggs 

 appeared. I at once looked for the queen but 

 found none. No one ant in my colony was any 

 larger than her sisters, and I was mystified as 

 to the source of these eggs. However, they con- 

 tinued to appear; and there have been reared in 

 this nest up to date at least three complete broods. 

 We naturally expected that the eggs which were 

 evidently laid by workers would produce males 

 as is the case with bees. But this theory was 

 wi'ong, for all the eggs laid hy the ivorkers in this 

 nest have developed into workers. I have never 

 been able to observe the actual process of egg 

 laying. I am ratlier inclined to believe that the 

 eggs were usually produced during the night. 

 There was nothing in actions or appearance that 

 enabled me to distinguish the egg-laying indi- 



