(1688) Leeuwenhoek here also devotes much attention to the circulation of the blood of higher animals , in particular that of the bat .Letter 119 ( 71 ) is devoted to the life cycle of the corn - moth ; on the basis of the fundamental investigation not only does he devise a system for combating this noxious incset , but he also describes an experiment performed with it .So far about the ( broad ) contents of the letters of Volume 8 .