BUREAU OF ANIMAL INDUSTRY. 



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peratnre of 20° or 25° O. (68°-77° F.) we have been unable to keep them 

 alive for more than eight or ten days, whilst at a lower temperature 

 they lived for many months, almost a year. During this time they 

 molt, the tail becoming less elongated, and assuming the form of a 

 short cone (Plate II, Fig. 10). When the hatching has been delayed 

 from insufficient warmth, and the embryo finally escapes from the egg, 

 it leaves within the shell an envelope. This fact seems to prove that 

 the molt, which takes place normally one or two days afterbirth, occurs 

 in the egg itself when birth is retarded. In the experiment glasses hi tfm 

 with short tails were often seen moving among those with long tails. 

 The former were simply older than the latter. 



The following questions now arise: Does the larva molt a second 

 time before assuming the adult form, and what are the ways and means 

 employed by it to reach the only place where adult and paired syn- 

 games are found — the trachea of birds? 



Some species of Sclerostomata presents a nymphal phase, during 

 which the young parasite is provided with an almost complete buccal 

 armature, and lives, rolled up and encysted beneath the mucous mem- 

 brane to which it attaches itself in its adult state. Kepeated investi- 

 gations have failed to reveal anything analogous in the syngame of the 

 pheasants. We have every reason to believe that the nymphal stage, 

 no doubt very short and active, is passed in the air-sacs and pulmonary 

 bronchi, which, as is well known, intercommunicate very largely in 

 birds, ; :ul which the larvae may readily reach by traversing the intes- 

 tinal or (esophageal tunics after escaping from the ingested eggs. We 

 also believe that the parasites very soon after reach the trachea, to be- 

 come adult, pair, and attach themselves. The following are the facts 

 upon which this opinion is based : 



1. The larvae of Syngaiuus, according to our observations, do not 

 develop well, nor will they leave the egg and become vigorous except- 

 ing in a moist and warm medium, approaching the conditions offered 

 by the interior of a bird's body. 



2. In a young pheasant, dead from the gapes, we found in the mucus 

 obtained by scraping the lining membrane of the oesophagus, a large 

 number of eggs of syugames with the shell opened and abandoned by 

 the embryo. We have preparations to demonstrate this fact. 



3. In the serous fluids which lubricate the walls of the air-sacs, more 

 particularly those in relation with the duodenum, we have found in the 

 case of young pheasants attacked with the gapes very active larva3, 

 almost twice as large as those just emerging from the egg, seeking 

 their way. 



4. In the cellular peritracheal tissue, in the neighborhood of the crop 

 of one of the young x>heasants referred to above, we found, stretched 

 out parallel to the trachea, a young female syngame, already colored 

 red, 5 u,nj (.2 inch) long, with the mouth formed like that of the adult, 

 and even sexually matured. We think that it was a syngame which, 

 having been delayed in the migration, failed to reach the mucosa oi the 

 trachea in due time and now could no longer do so, because the aduit 

 structure of the mouth-parts presented an impediment to its march 

 across the tissues. 



5. In the inclosures of M. de JanzC, at Gournay (Euro), which were 

 desolated last year by the gapes, and which have presented this year 

 some cases of this disease, the following fact has often been observed 

 and verified by M. de Janze* himself: The young pheasants affected 

 with this malady frequently expel, in a fit of coughing, plump, fat syn- 

 games full of eggs. The other fowls near by consume with avidity the 



