Descriptions of the eggs of Mansonia uniformis, Ma. indiana and Ma. annulifera are provided with the aid of scanning electron micrographs. Eggs of these three species, although similar in shape and colour, are covered by outer chorionic reticulum and tubercles which provide reliable morphological character for their identification. Size, distribution and number of lobes on the large tubercles present in the region between the anterior tube and posterior region, are important distinguishing features. Measurements of egg sizes and other chorionic differences are also discussed.
An immature merocyst of Hepatocystis malayensis and gametocytes of H. brayi were studied with the electron microscope. The merocyst consisted of a highly complex cytoplasmic reticulum ramifying through an amorphous matrix: the entire complex was enclosed by a simple unit membrane. The host cell was apparently destroyed completely during growth of the cyst. Immature gametocytes were highly amoeboid and showed extensive vacuolisation or attenuation of the cytoplasm. The nucleus contained one or two prominent nucleoli. Mature gametocytes had compact cytoplasm and contained pyriform osmiophilic bodies which were believed to function in the release of the parasites from the host cells. Macrogametocytes were distinguished from microgametocytes by cytoplasmic differences in numbers of ribosomes, and cristate mitochondria and in the extent of development of the smooth endoplasmic reticulum. The compact nuclei of the macrogametocytes had inconspicuous DNA but prominent nucleoli whereas those of the microgametocytes were irregular and showed a central aggregate of DNA. In microgametogenesis karyokinesis of the parent nucleus was delayed until axoneme formation was complete. Then the nuclear buds were extruded into emerging microgametes. At fertilisation the plasmalemmas of the two gametes fused and the single axoneme and nucleus of the microgamete moved into the cytoplasm of the macrogamete.
The egg structure and outline of the embryonic development of Metallyticus splendidus of one of the basal Mantodea representatives, Metallyticidae, were described in the present study. The results obtained were compared with those from the previous studies, to reconstruct and discuss the groundplan of Mantodea and Dictyoptera. In M. splendidus, the egg is spheroidal, it has a convex ventral side at the center in which numerous micropyles are grouped, and it possesses a conspicuous hatching line in its anterior half. These are the groundplan features of mantodean eggs and the "grouped micropyles in the ventral side of the egg" are regarded as an apomorphic groundplan feature of Dictyoptera. A small circular embryo is formed by a simple concentration of blastoderm cells, which then undergoes embryogenesis of the typical short germ band type. Blastokinesis is of the "non-reversion type" and the embryo keeps its original superficial position and original orientation throughout embryonic development. During the middle stages of development, the embryo undergoes rotation around the egg's anteroposterior axis. These features are a part of the groundplan of Mantodea. It is uncertain whether sharing of the "non-reversion type" of blastokinesis by Mantodea and blaberoidean Blattodea can be regarded as homology or homoplasy.
Three cases of schistosomiasis in 2 Filipinos and one Chinese in Sabah are reported. Diagnosis was based on incidental histological findings of Schistosoma japonicum-like ova in the liver and rectal biopsies. As these 3 patients are immigrants to Sabah, it is assumed that they are imported cases, and that Sabah has been free of the disease from 1970 to 1977.