sentence1: however , since the sperm head is slender and short compared with the overall length of the flagellum of actual insect spermatozoa , the extra resistant forces and torques created should be insignificant .
sentence2: furthermore , since actual insect spermatozoa heads are very slender and short compared with the entire length of the flagellum , the contribution of its hydrodynamic resistance and the hydrodynamic interactions with the flagellum should be negligible .