328 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I4I 



different stages of development ; he continued, "it is only where the 

 molts are very abundant that one loses sight of this familial habit." 

 Tillyard (1926) also stated that the Australian species of Panesthia 

 live in burrows in soil in strict family communities of a pair of adults 

 and 10 to 20 nymphs. A related colonial species, Cryptocercus punctu- 

 latus, lives in both sound and rotten logs in colonies consisting of a 

 pair of adults and 15 or 20 nymphs, probably representing two or 

 three broods (Cleveland et al., 1934; Cleveland, 1948). Chopard 

 (1938) has cited this association as an example of gregariousness, 

 which it may well be ; however, the presence of only one pair of 

 adults in each colony suggests a more intimate relationship. 



Among species of Blattella and certain other genera with similar 

 reproductive habits the female carries her ootheca clasped in her 

 genital cavity with the posterior portion projecting behind her. Each 

 normal ootheca is carried for approximately the duration of embryo- 

 genesis and is not dropped until, or shortly before, hatching. We have 

 seen (1954, fig. 65) newly hatched nymphs of Blattella vaga crawl 

 over the body of the mother who stood quietly near the dropped 

 ootheca ; this female raised her wings and some of the nymphs 

 crawled under them onto the dorsal svirface of her abdomen. The 

 nymphs seemed to feed on the grease covering the mother's body. The 

 association was short-lived, however, and soon the nymphs scattered. 

 Pettit (1940) stated that when hatching of Blattella germanica occurs 

 in the open (on a table top), the nymphs may remain near the capsule 

 only a few minutes. Ledoux (1945) found that newly hatched 

 nymphs of 5. germanica remained together without shelter in a single, 

 sparse group. If the nymphs were separated by blowing on them, the 

 group quickly reassembled, usually in the same spot. Ledoux showed 

 that this gregarious grouping of first-instar nymphs was not neces- 

 sarily a familial association by placing nymphs from two oothecae to- 

 gether. In groups of 8 to 12 nymphs there was a perfect intermingling 

 of the offspring from the two different females. 



It is among the so-called viviparous cockroaches that the greatest 

 number of observations have been made of postparturient associations 

 between female cockroaches and their offspring. The females of these 

 species carry their oothecae in brood sacs within their bodies until 

 embryogenesis has been completed. This behavior ensures protection 

 of the young from desiccation and attack by parasites (Roth and 

 Willis, 1955a). (See Roth and Willis, 1958a, for an analysis of ovi- 

 parity and viviparity in the Blattaria.) Shelford (1906, 1916) re- 

 ported that he had captured a female of Psendophoraspis nebitlosa in 

 Borneo with numerous young nymphs clinging to the undersurface of 



