the galaxies because their velocities are mostly close to escape, but adiabatic expansion against external gas tends to hamper this.

As an extreme, [@bab92] speculated that galactic winds are able to empty DGs from its fuel for subsequent SF and, by this, transform a gas-rich dIrr to a fading gas-poor system. In order to manifest this scenario and to study mass and abundance losses through galactic winds numerous numerical models are performed under various, but mostly uncertain conditions and with several simplifications (e.g. [@mlf99; @str04]). The frequently cited set of models by MacLow & Ferrara [@mlf99] (rotationally supported, isothermal disks of dIrrs with fixed structural relations for four different gas masses between M$_{\rm g} = 10^6 - 10^9 \Msun$ and three different SNII luminosities in the center corresponding to SN rates of one per $3\times 10^4$ yrs to 3 Myrs) is mostly misinterpreted: The hot gas is extremely collimated from the center along the polar axis, but cannot sweep-up sufficient surrounding ISM to produce significant galactic mass loss. On the other hand, the loss of freshly released elements from massive stars is extremely high. Moreover, these models lack of realistic physical conditions, as e.g. the existence of an external pressure, 