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SUMMARY OP CURRENT RESEARCHES RELATING TO 
in the dorsal covering of the head, bnt they form most of the cheeks. 
(4) The “ sutures ” on the head of the adult only partially correspond 
to the original regions in the embryo ; in fact they appear also in places 
where in embryonic life there are no boundaries. (5) The “ dorsal 
organ” appears internally in the posterior region of the head. (6) 
What have been hitherto called labial palps are the lobi externi ; 
Meinert’s “ verruca oblongae ” are the labial palps. (7) What is called 
the ligula is formed from the sternite of the first maxillary segment ; 
the two parts called paraglossae arise from the sternite of the mandi- 
bular segment ; and the three parts together should really he regarded 
as hypopharynx. 
Gonads and External Genital Appendages of Plecoptera.* * * § — Herr 
Fr. Klapalek was led to study these organs because of their value in 
classification. This is particularly true of the Plecoptera or Perlidse. 
He describes a dozen species as regards the structure of the parts in 
question, and then discusses some related morphological questions. He 
comes to the general conclusion that both the internal organs and the 
external parts are more primitive in Perlidse than in any other insects, 
including the Apterygota. 
Viviparity of an Ephemerid.f — Sig. A. Coggi returns to a discus- 
sion of the discovery of viviparity in Cloeon dipterum L. We need not 
enter into the details, though they have doubtless their interest; the 
point is that the viviparity of this mayfly, vaguely announced by 
Siebold, was discovered and studied by Luigi Calori in 1848, and, after 
having been for long ignored by many, has been recently confirmed. 
Tetrameric Regeneration of the Tarsus in Phasmidse.J — M. Edmond 
Bordage has shown that, after autotomy or amputation of a limb in larvae 
or nymphs of Phasmidse, a regeneration occurs in which the tarsus has 
only four instead of the usual five joints. He gives particular details 
in regard to Monandroptera inuncans. Bateson and Brindley have cited 
such cases in Blattidae as examples of discontinuous variation (“ variation 
brusque ”), but Bordage thinks it “ much more logical ” to regard the 
occurrence as an atavism, as a return to an ancestral condition similar 
to that which may still be seen among the Locustidae. 
Natural History of Ants.§ — M. Charles Janet publishes an admirable 
lecture on the habits and life-history of ants. Taking as his type the 
common little red ant, Myrmica rubra , he first describes the successive 
stages in the life of the individual, noting, as an instance of abrupt 
change in animal habit, that while many larvae spin a perfect cocoon, 
others of the same species spin none at all. He then discusses poly- 
morphism, comparing the functions and status of the queens and workers 
of an ant-colony with those of bees and wasps, and tracing the fate of 
males and young queens after the nuptial flight. The males are allowed 
to die or are pitilessly killed, while such of the females as can be found 
are brought back to the nest to add to the number of its queens, and the 
rest creep away into holes to lay their eggs and laboriously found a new 
* SB. Akad. Wiss. Wien, cv. (1896) pp. 683-738 (5 pis.). : 
t Anat. Anzeig., xiii. (1897) pp. 498-9. 
X Comptes Rendus, cxxiv. (1897) pp. 1536-8. 
§ Paris, 8 vo (au siege de la Soc. Zool. de France), 1896, p. 36. 
