April i, 1892. J 



SCIENCE. 



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questions that are pressing upon the attention of Congress, 

 there is none more important and exigent than attention to 

 this matter which has been brought up by the senator from 

 Connecticut. I do not believe we can afford to wait a single 

 day in giving our attention to some method of relief. I un- 

 derstand from the report made by the secretary of the in- 

 terior that the quantity of air to each individual ia the part 

 of the building where these ladies worked is about 400 cubic 

 feet, whereas Dr. Billings, the best authority perhaps in the 

 United States or in the world on sanitary matters of this 

 kind, says that human life cannot be healthfully continued 

 without something like 4,000 cubic feet to the individual. I 

 asked the gentleman who has charge of that room how they 

 managed to get along at all, and he said that at intervals of 

 about two hours or an hour and a half they had to ask all 

 these people to go out of the room — in winter time, of course 

 — so that they might raise the windows in order to change 

 the air; otherwise they could not get along as well as they 

 do. That condition of things is shameful as well as deplora- 

 ble, and I think some action ought to be taken at once in 

 the interest of the human beings who are compelled by 

 their necessities to perform their duties under such circum- 

 stances.' " 



THE STRUCTURE OF THE HEMIPTEROUS MOUTH. 



Our knowledge of the mouth parts of the Heraiptera is 

 given by Professor Comstock in his valuable " Introduction " 

 as follows: " The mouth parts are formed for piercing and 

 sucking. Without dissection they usually appear as a slen- 

 der, jointed beak, arising at the base of a shorter, pointed 

 labrum. This beak consists of four bristles inclosed in a 

 fleshy jointed sheath. Two of the bristles represent the 



mandibles and two the maxilla;. The sheath is supposed to 

 consist of the labium and growutogether labial palpi. Tliis 

 sheath is usually four jointed, and is never composed of 

 more than that number of segments. The maxillary palpi 

 are wanting." The results of my studies in the Diptera, 

 Hymenoptera and on the pupa of Cicada, lead me to disagree 

 with this explanation, or homology, of the parts. 



The head of a Cicada pupa when softened and cleaned so 

 that all the parts are easily recognizable, shows four divis- 

 ions, or sclerites, forn)ing the lateral margin of the head in- 

 feriorly. In Fig. 1 the sclerites are shown, pried apart for 

 convenience of recognition, and without attempt at any but 

 diagrammatic result. The anterior of the sclerites is the 

 labrum, covering the base of the mouth, and normally ap- 

 pressed so close to the beak that the intervening structures are 



not visible. Behind the labrum and normally closely united to- 

 it is the mandibular sclerite, which has not been heretofore 

 recognized, but which is exactly where it should be, com- 

 pared with a mandibulate mouth. From the side this sclerite 

 gives a mere indication of its character and from the firm- 

 ness of the union shows that the mandibles are not mobile 

 and therefore not functional. Cutting along the posterior 

 suture of the mandible and then straight across so as to get 



the whole of the labrum, we get from behind the view shown 

 in Fig. 2. Here the mandibles show as elongated flattened 

 strips, quite chitinous in texture toward the tips, which lat- 

 ter are acute and somewhat beak-like, divergent. The ex- 

 tremities lie so close to the pointed tip of the labrum that 

 they are invisible from the side. In the cavity between the 

 mandibular sclerite and the front of the labrum there is at 

 least one large gland, probably that secreting the irritating 

 fluid which many bugs inject into the punctures made by the 

 beak. From this gland a distinct duct leads to the pointed 



tip of the labrum behind and between two chitinous wings 

 giving muscular attachments. In Belostoma the labrum is 

 extended so as to cover the beak for half its length. Here 

 there is a salivary gland behind the clypeus, the duct extend- 

 ing to the tip of the labrum and then apparently discharging 

 into the beak. In some species the labrum is set inwardly 

 with a coating of very fine, dense hair, giving a velvety sur- 

 face, and this, as Dr. Packard has shown is the epipharynx. 

 It is not present in the Cicada pupa. The sclerite next he- 

 hind the manibular ring is that from which arise the two 

 bristles that are usually homologized with the mandible and 



