PHYLOGENETIC ORIGIN OF TERMITE CASTES. 125 



of the first form probably produce the nymphs of all three repro- 

 ductive castes. At the proper season of the year before the 

 time of swarming nymphs of the first and second forms are 

 commonly found together in colonies, although colonies have 

 been found in which no nymphs of the second form have been 

 observed. Nymphs of the third form have never yet been found, 

 which may be due to their resemblance to the young of the 

 other castes; there is a possibility, however, that the individuals 

 of the third form may be fertile workers, a point to be determined 

 by morphological data, and now being investigated by one of the 

 authors. 



Both field observations and breeding experiments seem to 

 indicate that the second and possibly the third forms produce, 

 in addition to the sterile workers and soldiers, only their own 

 fertile types, and never nymphs of the first form. In other 

 words, the second and third form reproductive adults apparently 

 breed true to their fertile types. In some artificial colonies with 

 parent reproductive individuals of the second form, no repro- 

 ductive forms but only sterile workers and soldiers have been 

 produced. This seems to be the case in the two following ex- 

 periments. 



The Rev. F. L. Odenbach received in September, 1900, a 

 small colony of termites, Neotermes castaneus Burm., from Florida. 

 He placed these insects in an artificial nest and has continued 

 to make observations on their habits. On July I, 1902, eggs 

 were found in the nest. In February, 1908, about one hundred 

 and fifty members were present in the colony. In September, 

 1908, and again in June, 1909, reproductive forms were observed 

 in the nest, much larger than the other members of the colony, 

 and some with an enlarged abdomen, the body segments appear- 

 ing as prominent chitinous bands, due to distention, a charac- 

 teristic of the older termite queens. From Odenbach's descrip- 

 tion these were evidently reproductive individuals of the second 

 or third form. In December, 1910, approximately two hundred 

 individuals were in the nest. This colony was still alive in 

 September, 1917. Workers and soldiers, but no forms with 

 wing pads nor any winged adults, have been produced in this 

 colony after seventeen years of breeding. 



