When it is in the hollow cell, the hollow cell takes the food and propels it into little tubes, which are lined with flame cells. These flame cells contain small cilia, these cilia pushes the waste from the flame cells to tubules that excrete the waste from the proglottids.
Attachment size limit. You can send up to 25 MB in attachments. If you have more than one attachment, they can't add up to more than 25 MB. If your file is greater than 25 MB, Gmail automatically adds a Google Drive link in the email instead of including it as an attachment. The person you send the file to can download it so they'll have access to it even if you remove it from Google Drive.
Note that all these size limits are based, not on the original file size, but the MIME-encoded copy. The common Base64 encoding adds about 37% to the original file size, meaning that an original 20MB file could exceed a 25MB file attachment limit. A 10MB email size limit would require that the size of the attachment files is actually limited to about 7MB.