Rotarides Mihály (szerk.): A Magyar Természettudományi Múzeum évkönyve 33. (Budapest 1940)

Tóth, L.: The protein metabolism of the Aphids

cannot play an essential part in the protein provision of the host. Of greater dimension and of quicker process is the solution of the symbionts, although a phenomenon less general. Its essence is, that an oenocyte gets in touch with a cell, containing symbionts, the mycetocyte, unites with it and thus discharges into it the contents of its vacuoles. As a consequence, the nucleus of the mycetocyte is first destroyed, and later, the symbionts get dissolved. Their places are indicated by great vacuoles, the cell itself becomes spongy, and later the oenocyte itself gets abolished. Generally, several neighboured mycetocytes are degenerating at the same time, so that a fairly great mass of symbionts will dissolve that way. It is conspicuous, that whilst the degeneration of the phagocyted symbionts is a very slow process, the solution here is a quick one, though the two processes are very much like each other. The difference of time may best be explained by the fact, that the bacteriolysin, produced by oenocytes is increased in its effect by material, produced in the degenerating nucleus. Much more important, however, is the third way of symbiont solution. For the infection of the embryos of the quickly multiplying Aphid, great masses of symbionts get into the body cavity every day. A part of them is taken up by the embryos themselves, the other part gets dissolved in the body cavity. The quicker the multiplication of the host, the greater its protein needs — the more symbionts get dissolved in the body cavity. As, unfortunately, the process of the symbiont solution is not intracellular in this case (as it is going on in the body cavity itself), its tracing is rather difficult. But it can be stated, that: 1. In each Aphid, there are to be found oenocytes, filled with excrete vacuoles, which pour their content into the body cavity. 2. The nucleus of the discharged mycetocytes get degenerated and the material thus gained gets into the body cavity. Against this, the condition of the second way of the symbiont solution, mentioned are given. The only difference is that the process is not intracellular. In all three ways of symbiont solution it is important that the symbiont proteins in dissolved condition serve to the benefit of the host. Now let us see, if the problem can be decided, whether symbionts are really active protein providers for Aphids in such sense, as they are in the generally known case of the Leguminous family? Unfortunately, proofs are circumstantial and difficult to bring If one could state, by exact researches, what the protein quantities are, which have been taken up by the nourishment and discharged