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SPOROZOA. GREGARINA.

Remove the head and posterior end of a larval or adult meal beetle and pull out the digestive tract with a pair of forceps. Place the digestive tract on a slide, split it open length- wise with a sharp scalpel, and then spread it out, with the inner wall exposed, and cover. The operation should be performed rapidly to prevent the material from drying. If the beetle is infected, numerous gregarines will be visible under the microscope. Study with low and high powers.

  1. Does the animal move? A great number of refractive granules are present in the protoplasm. They are regarded as reserve nourishment. They can be removed with acid.
  2. Note that the body is covered with a membrane, and is divided into a dense superficial layer, the ectoplasm, and a central, more fluid mass, the endoplasm.
  3. The endoplasm is separated into two parts by a portion of the ectoplasm. The anterior part is termed the protomerite, and the posterior part the deutomerite. In which is the nucleus situated ?
  4. Is it possible to distinguish a layer of myonemes just external to the endoplasm?
  5. Is there another section of the body just anterior to the protomerite? If so, this is the epimerite.

Before reproduction Gregarina throws off the epimerite, leaves it in the cell-host, and falls into the lumen of the digestive tract. It then encysts, and the protomerite and the deutomerite form one spore-producing individual. The attached stage in the life-history of Gregarina is termed the cephalont, and the detached stage, the sporont.