. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. THE MEDIAN EYE OF SOME SOUTH AFRICAN PALINURIDAE 97 pigment. nuclei of sensory cells Fig. Panulirus omatus. Section of median eye of a 19 mm puerulus stage. The large lateral cups are separated by a broad band of pigment. band of pigment (fig. 8) divides the eye into two large lateral cups and a relatively small ventral cup. Up to 15 sensory cell nuclei are apparent in each lateral cup, but cell boundaries are indistinct. Only one large nucleus is evident in the ventral cup, and the presence of rhabd
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. THE MEDIAN EYE OF SOME SOUTH AFRICAN PALINURIDAE 97 pigment. nuclei of sensory cells Fig. Panulirus omatus. Section of median eye of a 19 mm puerulus stage. The large lateral cups are separated by a broad band of pigment. band of pigment (fig. 8) divides the eye into two large lateral cups and a relatively small ventral cup. Up to 15 sensory cell nuclei are apparent in each lateral cup, but cell boundaries are indistinct. Only one large nucleus is evident in the ventral cup, and the presence of rhabdomes is uncertain. Characteristically, the median and lateral nerves of the eye lie between the pair of apical nerves. Their association with the protocerebrum is obvious, but the passage of the axons through the cups is more obscure than in the median eye of the puerulus stage of J. lalandii. The eye is enclosed in a thin wall which is continuous with the epineurium, and the lateral cups are connected with the epidermis by a pair of dorsal tubes. The presence of the latter suggests that the paired dorsal frontal organ is represented in the lateral cups. The ventral frontal organ is imperceptible and is probably lacking. 6. Panulirus homarus — immature From an examination of sections of the median eye of two animals ( 45, 53 mm), it has been concluded that, as in J. lalandii, there is a progressive deterioration of the organ in post-larval stages. The smaller specimen is an immature male in which the median eye (fig. 9) is rather reduced but still has the form of a fairly well-developed organ. It is situated at least 45 /j, above the brain and measures about 40 /x high, 110 /x wide, and 120 fx long. The whole is a compact structure enveloped in a broad band of epineurial fibres and surrounded by connective tissue which is less dense than that observed in the adults of J. lalandii. Although most of the pigment is scattered, in places it is massed together and separates t
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
