Book excerpt: In this study, the functions and mechanicalinteractions of different parts of the secondary copulatory apparatus ofAnisoptera are reconstructed in detail and possible evolutionary pathways aredescribed. Whereas in Zygoptera and Anisozygoptera the vesica spermalis of thethird abdominal segment is a single segmented intermediate sperm-storage, thisorgan is subdivided into four segments in the Anisoptera. The evolutionaryconsequences of acquiring new functions as secondary (in reality tertiary)"penis" and sperm-syringe are one focus of this study. The secondary copulatoryapparatus of male dragonflies (Odonata), located at the second and thirdabdominal segment, consists of a number of sequentially arranged devices.These serve (1) as support of the female ovipositor, (2) for carrying outpreparatory actions for filling an intermediate sperm-storage, (3) for leveringand inserting a secondary "penis" (in the primitive case the ligula) and (4) astransmitter of sperm to the female vagina. Each subtask affords a sequence ofactions of the corresponding sclerites and muscles of this apparatus.An impressive variety of different solutions to perform and secure the fillingof the sperm-reservoir of the vesica spermalis in the Anisoptera isdescribed. In the primitive case a laborious and time-consuming procedure - which probably depends on interrelated functions of the ligula and female ovipositor - is carried out. Reduction of the ovipositor in different lines of the Anisoptera apparently initiated evolutionary modifications, which finally led to more sophisticated modes of preparing filling and protection. Another focus are the auxiliary devices and techniques in the Anisoptera for emptying the sperm-reservoir of the vesica spermalis. For instance, two different types of sperm-pumps are incorporated in its distal segment ("glans"). These pumps - which extend the function of a hydraulically working gland-structure, the erectile organ - show an opposite co-ordination of sperm-suction and -ejection in connection with compression and decompression movements. It was tried to reconstruct a transitional system to close a serious gap in the phylogenetic interpretation. A comparative investigation of different "glans" led to the discovery of different "ways" of combining the emptying-mechanism of the sperm-reservoir with an intensification of the sperm-jet and a "washing out" of sperm of the male predecessor (sperm displacement). The different stages of evolution of the glans, which reflect phylogenetic splittings, are outlined and discussed. This study is of great interest to biologists interested in the functional morphology of the Odonata. It does not merely rely on painstaking comparisons of morphological details, but integrates functional points of view to use the heuristic power of hypothetical approach.