The Formation and Structure of the Micropylar Complex in the Egg-Shell of Rhodnius Prolixus Stähl. (Heteroptera Reduviidae)

摘要: An investigation has been made of the junction between shell and cap in egg-shell Rhodnius prolixus. This complex region consists thickened rim connected by a thin sealing bar to shell. The secretion this part followed compared with formation less specialized portions divided into units, each product an individual follicle cell. It found that all seven layers which make up unspecialized parts are present seal complex; these consist five endochorion two exochorion their normal order. is secreted around long villi, one from These give rise follicular pits In region, cells start secrete at various stages seven-phase cycle; initial apparently related material they contact time. After started, cell completes remainder cycle. four rings cells; additional thickness achieved increase layers, series very pits. bar, produced ring cells, composed inner chorion only; do not produce soft endochorion, or layers. At end there predetermined hatching line. presence inactive during so prevent co-ordination active on either side. A weak point also base site other though fissure used hatching. similarly expansion villi. Of these, three filled towards secretion, but fourth, lying upper portion rim, remains. become micropyles associated structures. There 200 completed groups. About fifteen micropyles; cavities closed end, name ‘pseudomicropyle’ given. pseudomicropyles formed similar way pits, resistant protein layer, 0.5µ inside They exochorion, where external surface small bunches pore canals. probably play some respiration embryo. true form only free path through tube lined hydrophilic protein, outer portion, lies slightly posterior pseudomicropyles, hydrophobic lipoprotein. number constant, being ten twenty scattered irregularly rim. However, eggs older females contain fewer may account for higher rate sterility among eggs. ones adhere typical cycle secretory products. But omitting phases, attachment layer retained. Evidence suggests forming determined earliest squeezed out pseudomicropylar cells.