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The ova determined in the stools were those of the genera Ascaris, Tricho- cephalus, Ankylostoma, and, in one instance, I saw two which appeared to be the eggs

of Bilharzia, but long search failed to reveal further examples, and of this point I cannot be certain.

No evidence of the presence of Cestode or Trematode parasites was obtainable. The Ankylostome eggs did not appear to differ in general features from those of Ankylostoma duodenale, save that there was'a very slight difference in measure- ment between those usually given and those obtained by me in these cases.

Length

Breadth

Pigmy Ankylostome.

Ankylostoma Duodenale.

068

-034

-055-065

-032-043

In all these cases I found a very few eggs of the whipworm, Trichocephalus. Here, again, there were observable slight differences from the ova of the English species (Trichocephalus dispar). The minute details are not identical, yet the divergencies are so small as to make it exceedingly doubtful whether they are not mere variations. The "plugs" do not give the same convex " lens-like" appearance as that characteristically seen on Trichocephalus dispar. The measurements are as follows:-

Length

Breadth

Pigmy Triohocephnha

Triobocephalus. dispar,

'0425

-056-036

*0225

·026-021

The Ascaris ova, found only in the youngest male-Mongongu-were in fair numbers, and presented greater divergencies from the typical human Ascaris eggs (Ascaris lumbricoides) than did the other eggs from their types. It is indeed possible that they are the sexual products of a new human Ascaris, differing, as they do, in size, shape, and minutiæ of structure.

My measurements of the ova show a uniform width of '042 mm., associated with a breadth varying in different specimens from 068 mm. to 085 mm. The ova of Ascaris lumbricoides are considerably more rotund, and while the limits of length and breadth differ but little, yet we have not as a common associated the com- bination of minimum breadth with maximum length which obtains so uniformly in the Pygmy Ascaris.

Length

Breadth

MEASUREMENTS.

Ascaris lumbricoides

socording to Braun,

Pygmy Ancaria.

(a) 085

(b)

-075

(c) 065

-05 to 07 (limita).

-042

..042

042

-05 to 05 (limits).

In appearance, too, apart from the difference in outline, the Pygmy ascaris ova have a thinner covering, and the corrugated surface seems sharper than is found usually in Ascaris lumbricoides.

Whether the adults represent a new human ascarid parasite, as is possible from the above-mentioned comparison, or are merely Ascaris lumbricoides, the ova of which, owing to some undetermined cause, have undergone a change in shape and size, can only be determined by an examination of the mature parasites. So far no chance has occurred of settling this interesting question. The same may be stated for the other eggs in which I have described differences.

In May of this year Dr. Massey, of Benguela, Portuguese West Africa, forwarded for description and identification a worm found by him in the stools of

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a native youth, age 21, who had been under his care for indefinite intestinal symptoms. There was only one specimen, a female with the posterior extremity damaged. It had been through several hands previously for identification, and was in a bad state of preservation.

On examination the three characteristic jaws seen placed it in the genus Ascaris, but in other respects it differs from previously described species of that genus found in human beings:-

(A) From Ascaris lumbricoides, in the presence of a well-developed muscular œsophagus, opening by a valve-like aperture into the intestine.

(B) From Ascaris mystax, which is exceptionally found in man, by the absence

of alæ.

In that the specimen is only a female, and is, moreover, damaged, we are deprived of several details necessary to fully determine its specific characters, or to decide definitely its relationship to the Ascarides of the lower mammals.

It resembles the Ascaris texana, found for the first time in America last December, and, like it, is more closely allied to the reptilian and avian than to the mammalian Ascarids.

In addition to work in human helminthology the following species of verte- brates (mammalian, avian, reptilian, and piscine) have been examined, and I hope later to present a detailed account of the parasites found :-

Chrysotis caymanensis. Cervus duvancelli.

Lorius lorys.

Cercopithecus Campbelli. Pteropus meduis.

Lacerta ocellata. Salamandra maculosa. Cercocebus collaris. Cercocebus aterrimus. Coracopsis vasa. Octyphaps lophotes. Chalcides tridactylus. Bellongia penicillata. Palæornis eupatria. Testudo elephantina. Malacochemmys terrapin.

Scincus officinalis. Hemitragus jemlaicus. Microtis glareolus. Thaumalea picta. Caryophaga whartoni. Eryx johni. Liothrix luteus. Chrysemys picta.

Tarentola mauritanica.

Caiman sclerops.

Eremias rubropunctata.

Ovis tragelaphus. Anguis fragilis. Canis magellanianus. Potamochoeaus penicillatus. Strepsiceros kudu. Tadorna cornuta.

Chrysemys scripte elegans. Palicornis fasciatus. Grus communis.

Nicoria annulata.

Depyrymnus rufuscens. Cyrrhula grissiventris. Poocephalus robustus. Sarcidiornis melanota. Xerus setosus.

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